The first computer I owned was a Commodore 64, but I had been programming for 13 years by that point, and there were some computers I might as well have owned.
In high school I had pretty much exclusive use of an LGP-21 after my school day was over. This is a computer which makes the Timex one look like a Cray. 4 k of memory, 32 bit words. about 16 instructions, and the first assembly language code I wrote got translated by an assembler I wrote myself.
My first PC was one of the first AT&T PCs, made by Olivetti (great for running spaghetti code) which I got cheap from work as surplus. We then went the normal route through 286, 486, Win 95, Win98, XP, Vista, and Win 7 machines - all boring. The most interesting one I had home was a UNIX PC (7300). One group surplussed all its UNIX PCs and I got them, for free, for members of my group. I returned mine when I left AT&T, but only because I didn’t want to move it, not because anyone wanted it back. Very nice machine, with full Unix, a screen and a modem. I used it to browse Usenet from my basement, back in the early days.
My co-workers - the ones who go back to the punch card days - used to try to impress me with stories about their first home computer, because I’m younger than they are. I can’t match their university and professional experience, but I can hang when it comes to home computers. I started early. 
When I was about 7, my Dad brought home a TRS-80 model 1. I seem to recall got a hardware upgrade to enable upper lower case. And we did something…probably a firmware upgrade of some sort…to fix the printer with it, because it was reversing the cases on us.
We didn’t have a word processor of any sort. Dad wrote a simple line editor. I did a report for school with it, and surprised/confused my teachers by handing in something from a printer.
Ahh…good times.
Later, I had a Commodore 128, and then a series of boring PCs.
-D/a
The first computer I ever used was a TRS-80 at school, but it was quickly followed by a few Apple IIs and Macintoshes. The first computer we had in the home (unless you count the Colecovision) was an Apple II, either on long term loan for one of my Mom’s jobs as a non-profit bookkeeper, or cheaply purchased used from her employer or a friend after they’d upgraded. I don’t remember the specifics, but we ended up owning an old Mac Plus with the black nylon carry case under similar circumstances that I actually used heavily after moving out into the big bad world after graduating college in 1997. While in college I had just used computer labs to do my reasearching and surfing and emailing and chatting.
Geeking out with that Mac Plus with an external modem, dialup access and a shell account, surfing text-only with Lynx and reading mail in Pine 10 years after the computer had been originally purchased…was a pivotal turning point in realizing just how much of a geek I had grown up to be purely as a hobbyist.
To this day I’ve never taken a computer-related class aside from Word Processing in High School, and I have no doubt whatsoever that is largely because of how easy I found it to teach myself how to use technology thanks to the approach of Apple.
My first one was a Cosmac Super Elf.
After that there was a TRS-80, an Atari 800 and then I got my first PC, an XT clone. Dual floppies!
I had a 386, a 486/25 a 486/66 and many more Pentiums including at least one from each generation, than I can remember. Currently running a quad core Q9450.
Commodore 64 (present)
My stepdads PC
Apple LC II (for college)
Mac Power PC clone (bought from friend)
iMac pedestal (bought)
iMac mini (brother hand me down) / iPod touch (refurbished)
next: perhaps a laptop??
84- C64
89- A500
95- A1200
01- P3 1GHz
04- XP 2800+
08- P4 3.2GHz
Still have them all (or at least bits of them), none work.
My ownership chain went:
Commodore Plus/4 - Garbage that broke immediately. It was a crap computer regardless and when my mother returned it, it was already discontinued and she was luckily steered into a Commodore 128 instead.
Commodore 128 - One of my old favorites and fond memories. I’ll admit it spent 95% of its time in C-64 mode but it was a great machine.
Tandy 1000 HX (8Mhz) - I still won’t shop at Radio Shack to this day on account of this piece of shit computer and the salesperson who took my hard-earned teenager dollars before I went off for college. It had extremely limited peripheral support (all Tandy products) which were discontinued about a week after buying it and a crappy Windows knock-off program. No hard drive; everything was off of floppies still.
Amstrad 6128 - I think it was this model. Someone gave it to me and it wasn’t anything fantastic but I used it a bit for WordPerfect and some DOS games. Oh, and I had Lemmings for it.
Packard Bell Legend (75MHz) - I’ve no idea what the model was but this was the last desktop I owned in the horizontal configuration where you’d set the monitor on top of the box. It was a first generation Pentium and has 8megs of memory as I recall. I mainly used it for the dial-up internet, DOOM and Civilization II. Ran Win95. I want to say it came with Microsoft Bob as well; I know it had some goofy “living room” style program manager.
Compaq with a K6-2 (500MHz) - Bought refurbished explicitly to play Everquest on. I think it was the cheapest box I could find capable of playing the game (it was maybe $200). Aside from the integrated graphics, it wasn’t a bad computer and I eventually bought it some cheap GeForce card.
Dell Dimension w/ P4 (1.8 GHz) - Still in use in the house after seven years, albeit as a family/email type computer. Running Win XP
i3 530 GHz - Current “real” computer.
My first one was a Tandy 1000EX (8086 with a 5.25" floppy). Damn thing was $1100. I stayed with Tandy through a 286 and a 386, , then a Compaq laptop, which I hated, then went to Gateway for a 486, then another Gateway (pentium, this time), and am now using a Lenovo Thinkpad T61 (Intel Core 2 Duo CPU, 2GB RAM) as a home computer, and an Asus Eeee Seashell notebook for travel/second computer.
I nursed my Commodore64 for years from junior high until I was in college. I wrote a 25 page research paper and was about to print it when…it died. Wouldn’t boot up. There was literally no one I could go to to get it running again, so I had to start typing the paper over, from scratch, on an old typewriter. I cried for a day I think. But I loved that thing. Had lots of games and a really nice word processing software.
I got my first Windows PC in 1998, a Compaq that ran for years even after I upgraded to a different model with more memory.
I currently have an ASUS and love it to pieces.
Yeah, they were pretty useless. I don’t even know if Windows was on the market when those came out (or at least when I bought mine in about 1986). It was strictly a DOS screen. I had a pirated copy of Multimate on floppy (like you say: no hard drive) and thought I was pretty cool. But you really couldn’t do much of anything meaningful with that computer. I did manage to teach myself how to manipulate some DOS settings through trial and error, though. And no internet then, either, so the whole thing was just an expensive typewriter.
1979: Ohio Scientific Challenger 4P MF. I had already been programming for several years, on IBMs, Crays, DECs of various types, but this was the first computer that was mine and on which I didn’t have time or money limitations. That was freedom. Two 5" floppy drives, maxed out at 48K of RAM, Basic, UCSD Pascal, and assembly language. I really liked programming that 6502 in assembly language. I bought a modem – the kind you set a phone handset into – but it came with no software, so I wrote my own terminal emulator for it. Dialed in to my universities’ computers and the ARPAnet. Went with me to grad school.
It died in a thunderstorm from the surge from a nearby lightning strike. That’s when I learned about surge protection.
1984: Macintosh. The first one, 128K of RAM, 3.5" floppy drive. Later upgraded to the equivalent of a “Fat Mac” with 512K RAM through a third-party kit. Also added a hard drive later, a whole 20MB. That one lasted a long time.
1994: Power Macintosh 7100. I wondered if I might get 10 years out of this one, too, but it didn’t make it quite that long. Only 8 years this time.
c. 1999: Bondi Blue iMac G3, given to me by a colleague. The first computer I had that I hadn’t bought myself. From this point on I’ve almost always had at least two computers operating in the house, which is good considering that by this point I had a wife and two kids who also wanted to use computers. Didn’t make the move to the new house in 2004.
2002: Power Mac G4 (Quicksilver), 933 MHz. I might have kept this one active longer except the main hard drive started to fail and it gave me a good excuse to buy a new computer. I’m going through them quicker – this one lasted only 7 years.
c. 2005: Gateway PC. We were down to one computer again and my oldest son wanted a second and also wanted to pay for it himself with money he had saved. So he did his own research and settled on an inexpensive Gateway as what he could afford. I bit my toungue and accepted that we were now a Mac and Windows household. Later we upgraded the graphics and memory so we could run Vista on it, just to do it, really.
2009: iMac 3.06 GHz Intel Core 2 Duo, 24" screen. My current main work computer at home.
2011: Custom built PC, i7 running Windows 7. This time I paid for it, but my son designed and built it. The Gateway had come to the end of its useful life and we needed another PC mainly for gaming for the kids and as a secondary to the iMac.
Not to mention the Dell laptop for my son to take to college, the iPad he got later, and the multiple iPods around the house.
RIP, Steve Jobs.
C64 was my first computer. After that, it was probably 8 or 9 years without a computer before I got a generic Windows 95 machine in 1997, then another generic Windows XP machine in 2003, then my current Windows 7 machine in 2009.
I’ve also had an iPod Classic and my current Android phone, but they don’t really count in this, I don’t think.
I got my first computer in 1999; the specs were: Pentium 2 processor running at 433 MHz, 64 MB of RAM, a 10 GB hard drive, and a 16 MB Diamond Viper video card. It ran Windows 98. I did a ton of gaming on that rig; but by 2002 it was getting too old to run the new games, so it was mostly used for MS Office and web surfing after that. I got a PS2 that year, so I moved away from PC gaming and didn’t return until last year.
By 2005 we wanted broadband but the computer was simply too long in the tooth (to upgrade to broadband through our ISP required Windows 2000 or better) - one of my dad’s work colleagues “harvested” some parts from old work computers and we beefed it up to a Pentium 3 processor (733 MHz), 512 MB of RAM, an 80 GB hard drive, a 32 MB TNT2 graphics card and Windows 2000 - still poor specs by 2005 standards but it did what we needed it to. I eventually got rid of this machine last year; it could still run MS Office 2003, but it was too underpowered to handle much else by 2010 (even animated banner ads on web sites would slow it to a crawl). I kept the hard drive to use for backup purposes.
In 2007 I got the laptop which I’m currently using to post this. It was one of the first Vista laptops. The specs: Core 2 Duo T7100 1.8 GHz processor, 120 GB hard drive and 1 GB of RAM (woefully inadequate for Vista! I later upgraded it to 3GB).
Which brings me to my current desktop which I built from scratch last June. It has a 2.7 GHz dual-core Pentium E5400 processor, 4GB of RAM, a 500 GB hard drive, a 1GB NVidia GTX 460 graphics card and runs Windows 7. I got back into PC gaming after deciding to forgo this generation of consoles - Steam has made it possible for me to catch up on many of the great PC games I’ve missed over the years.
Growing up:
VIC-20
Commodore 64
TRS-80
Commodore 128
Tandy Color Computer
Timex Sinclair, yes it was a pain to program, as I recall you had to put pauses in your code just to get the screen to show
As an adult:
Custom built Pentium II, 400MHz, 64MB RAM, running Windows NT4 (this was in 1999), upgraded in 2002 to a Pentium 4, 1.6GHz, 256MB RAM. I still have it, and it runs Ubuntu 10 (very slowly) now.
HP Pavillion laptop, 2007-2010, may it rest in peace. Its motherboard went on the blink one day and then died soon after.
Currently using an Acer Aspire laptop set up to dual-boot Windows 7 and Ubuntu 11.04.
At some point I started naming all my computers after Enya songs; the 2 extant ones are Boadicea and Ebudae while the deceased laptop was Sumiregusa.
I had played with a Wang mini in 1976 and a friend visited bringing his Apple II. I couldn’t understand what he wanted it for, but three years later we were writing a book together, he on his Apple II (which had been upgraded to allow both upper and lower case entry) and I was using a Teletype to sign on to a mainframe. My friend also signed to the same mainframe using Tymnet (in the US) and Datapac (in Canada). He used my account and that is how we exchanged files. Then I got an IBM PC in early 1982 (one diskette drive and 64 K of memory IBM-PCDOS without a version number), a Packard-Bell 286 machine with a 20 Meg hard drive and 1 Meg memory. Then I got a cheap ($700) Toshiba laptop that used DOS 3.11 (one of the better iterations) that died a couple years later and I replaced with another Toshiba that used DOS 6.?? and then a Win-95 machine that I still have and that I booted up within the last year to look for a lost file (it wasn’t there). After that an NT-machine, then an XP machine and a second one (all Toshiba laptops). A couple years ago I got an ASUS Netbook that I use when I travel. And earlier this year I got a Lenovo laptop that, alas, has Win-7. Around 10 years ago, I briefly had a Dell laptop, but it had a problem and the help line was frustrating and useless. I knew what was wrong, but they didn’t understand it well enough to follow my explanation and I returned it. And around 1990, I got a special grant to buy a Sun-SLC. Outrageously expensive piece of shit. After a couple years, I gave it away.