I started with a 50mm f1.8, because it was cheap. Then I bought someone’s whole kit off of eBay, which got me a 50mm f1.4, a 28mm f2.8, and a 70-210mm f4. Which covers wide-angle, normal, and zoom, and it’s all Canon stuff, so the quality is good.
Are there any other lenses you would recommend getting?
That sounds a good set up for allround use. After you have used them for a while you may find the need for either a Macro lense, or a longer focal length high speed lense. Since you bought off EBAY I guess you aren’t insanely rich, so stick with what you’ve got for now. Maybe get a few filters for enhancing effects, (a 2x magnifying filter can give you a very cheap approximation to a Macro lense). A good flash may be worth considering if you didn’t get one in the ebay bundle.
Second on Bippy. A macro is nice for extreme closeups, but takes getting used to the depth of field limitations. If you are going to do wildlife, I would recommend saving your pennies and buying something in the 500-800 mm zoom range. I haven’t used lens doublers for years, so don’t know if the quality has improved, but you might look into that as a cheap alternative to a thousand dollar zoom.
My Nikkor AI 105 mm f2.5 semi-telephoto takes some of the finest portrait shots. Past that, you’ve got the basic set up. With all those lenses, you might consider a spare camera back. A motor drive is always fun for fast action work.
Like Chefguy, I would recommend a larger zoom and a doubler.
If you cannot afford the zoom at this time, the doubler will allow for further shots, but you may need a decent tri-pod or some other camera mount as doublers can make for tricky shooting.
Depends upon what kind of photography you do. Macro lenses are always handy for flower shots or other very close-up work. I really like mine.
For making money and for snapshots, the lenses I use(d) most range(d) from 24mm to 200mm. I used primes for the money shots, and zooms for my snapshots.
When I’m out to really have some fun, I use extremes. I love to photograph through my telescope and I have even used eyepeice projection which nets me a focal length of about 3200mm and some ungodly f-stop. (OM-2, don’t have to worry about it much!)
At the other extreme, I love my 17mm. What an intersting way to look at the world. I try to purposely make it look as though it wasn’t a superwide I used. You really have to watch those lines! But, it is very cool to have depth of field from about 20" to infinity!
I also use a 35/1.4 (M-series) and a 50/1.2*(OM) for Henri Cartier Bresson type fun. I wish I had enough cash to get a Summilux 50 for my (really beat up) M-3. That would be sweet! (F/1.0) I also wish I had enough time to play with it all anymore.
That wide angle and extreme tele fetish of mine is also why I prefer the older cameras (less cost, usually), and haven’t lusted after digital SLRs (until recently the magnification factor of the small image sensor pretty much disallows extreme wide angle work.)
*yes, f/1.2. Sometimes, people would tell me their lense was a 1.2 when what they were reading off the lens was “50mm 1:2.0” which is an f/2.0 lens. This usually happened over the phone at the camera store I use to work at when they wanted a trade value estimate.
I’d consider a super wide angle lens. I shoot more with my 20mm Canon FD lens than with any of the others(28,50,50mm macro,135 & 70-210 zoom) that I have,especially if you use slide film.The angle of view is about 90 degrees.
Actually, depth of field is a function of apeture, along with focal length. I can still have a very long DOF with my 500mm lens, as long as my apeture is open as wide as it goes - in this case, f4.0, and can have a very shallow DOF if I stop it down to f32.
I also have the Nikkor 105 f2.0 macro. One of the best lenses I own or have used.
frank, you got it backwards.
And yes, I know that depth of field is a function of both aperture and focal length, but you get more DOF from a wider lens at any given f/stop. Extreme wides have inherently great depth of focus. That’s one of the fun things about using them. If you focused on something relatively close with a long telephoto, Even f/32 won’t give you the background in focus. Use an ultra wide, though, at the hyperfocal distance, and even at say f/8, you have a depth of focus that excedes what the human eye is capable of. That’s one of the reasons why ultra wides are fun. Try it! 
Second that.
I’m in pretty much the same position as you, SmackFu. My Canon EOS300 was bought with a two-lens kit: 28-80mm and 100-300mm zoom lenses. My main subject is landscapes, but I’ve found that I use the longer focal lengths just as often as the shorter ones.
My next planned purchase is for a wider angled lens. Possibly a 20-24mm zoom. I’ve already got a decent tripod and most of the filters that I need (polarising, warmup, graduated grey), and I’d rate all these as just as essential (for me) as the extra glassware.
Sounds to me like you have 95% of everything you need, as far as lenses go. I’d only check out other lenses if your preferred subject warrents it (e.g. longer focal length for wildlife, etc.)