I have Rhapsody, so I can listen to entire albums, but I can’t really recall the last time I bought a whole album, except the occasional 1/2-Price Books used CDs. Even then I’ll most likely rip the tracks I like and put them on my media player, and either shove the CD onto a shelf forever, or give it to a friend. I buy music by the track. I don’t buy vinyl – I do believe it’s possible some sound better than CDs but I’m not willing to spend the money and do the maintenance necessary to keep a musical system at that level of performance. Vinyl is dead to me. 
If I’m getting an album, I’ll check Amazon since sometimes you can buy the CD for equal or less than the MP3 version and it comes with “Auto-Rip” where you instantly get the digital version anyway.
For single tracks, I usually buy from Amazon as their download policy isn’t as draconian as Google’s three download limit (without downloading you entire library). Then I upload it to Google Music since I like their player better than Amazon’s.
I don’t buy music anymore. I have about 12 songs on my iPhone (which I’m quite sick of, as you can imagine). Most of the time I’ll listen to satellite radio for music (in my car) or Pandora at home or on a plane.
I’ll occasionally buy an album if it is something I know I’ll listen to multiple times over the years. I never buy individual tracks unless it’s part of a promotion where I can download a track for free. I use mostly Amazon and I’m mainly streaming on my phone or iPad. I also use Spotify, jazzradio.com app, or the Chamber Music Society of Lincoln Center app to stream music.
I buy CD and vinyl albums, and CD collections. I buy a few MP3 tracks too, but consider that ephemeral music, little different than a streaming service. It’s not “in the collection” if it’s not on physical media.
I haven’t purchased hard copies of anything since downloading/paying for a song became available. I built up a library of mp3s until about 2011.
Now I mostly listen to a shuffled selection on Pandora. Occasionally, I’ll check out music CDs from the library if I’m looking for something in particular.
My pre-internet CD collection still gets play rotation on my car CD/MP3 player.
I overuse YouTube, find things/artists I like then buy their CDs & DVDs.
Have only downloaded a handfull of songs not otherwise available.
I have Spotify, which I usually listen to at work on my phone. At home it’s Pandora or the cable Music Choice channels. We still have CD’s, but they’re gathering dust. I don’t have a CD player in the car, so I listen to the radio.
I probably have over 1000 vinyl albums, all from the days when vinyl cost *less *than CDs. I also have a few hundred CDs and quite a few cassette tapes from the old days. Nowadays, when I buy music, the format depends on what it is. For artists I really like, such as Bob Dylan, Springsteen, Paul Simon, Jackson Browne, Janis Ian and a few others, I will buy the CD so as to have it in my collection. Most other stuff, I will buy the mp3s as long as the price is comparable. Of course, if I find a bargain on CD at a thrift shop or something, I will grab that. But no matter what format I buy, it all gets imported to my iTunes library and winds up on my iPod, which is what I take with me to listen to music.
I buy CDs from Amazon, usually “like new” used ones, if available. Each new CD gets downloaded to iTunes, which now contains over 28,000 tracks.
After a couple of unexpected harddrive failures (internal and external) I’ve learned to rely on having a physical copy of the music (CD) I listen to, which I then consume mostly through iTunes. I also heavily use Youtube, now that it has loads of entire albums from my favorite genres. When I find something I really like there, I buy the CD, both to support the (obscure) artist and to have my physical backup copy.
I need to start buying actual CDs or LPs again. I got rid of everything thinking that I’d go all-digital, and then Apple started “losing” things that aren’t from Apple’s service. >:(
I have downloaded a few albums, yes.
I also like being able to download songs from bands whose albums aren’t great, but have a song or two I like.
I generally buy any format, but partly because I’m cheap. Some stuff on Vinyl is so cheap used that you’d be crazy not to buy it. Used CD’s are generally even cheaper.
Other times, it’s easier/cheaper to buy a digital copy than it is to find and buy a rare record. On top of that, there’s a lot of stuff that only gets released digitally.
I don’t use a service, they all seem to have some limitation technologically or in their available content that makes me uninterested.
I buy singles or whole albums from Amazon. I was buying a lot of their $5 albums several years back, so I’ve got a lot of music in my Amazon library that doesn’t really slay me but by now I recognize it.
Since Amazon’s Prime Music service started, I just grab stuff for free and put it in my Amazon music collection, and I play it on my Echo. If I want it and it’s not free on Prime (example, Missy Elliot’s new track) I purchase it through Amazon. I’ve got more music right now than I know what to do with!
Prior to the availability of Amazon digital downloads, I bought CDs.
I buy MP3s through Amazon or listen on YouTube.
When I listen to music it’s mostly in album formatMostly Spotify at home, but I’ll still buy new CDs for essential stuff that’s not on there; I bought a copy of T-Rex’s Electric Warrior the other week. I still have an extensive CD collection, which I’m not getting rid of: the streaming services are great, but I don’t trust them not to arbitrarily delete chunks of their catalogue or suddenly jack up their prices: they “lost” a bunch a Neil Young a while back. Plus I like shiny things. My CDs are all backed up on my laptop, but I don’t usually play anything in MP3 format unless I’m in the car or I just want a background soundtrack at home, because the compressed sound quality is too poor. I also scavenge the op shops for used CDs: at lot of people are getting rid of their hard collections, and I can often find stuff for a pittance that I was too poor to afford 25 years ago.
I tend to buy CDs from Amazon. As Jophiel pointed out, you also get a digital copy made available in your cloud library. You also have a physical copy in case the cloud ever goes tits-up. I can also download the album straight onto my phone without ripping the album from the disc.
CDs, often used, and I will occasionally download some songs, & burmn them to a disk.
I buy the occasional CD. Sometimes someone will download songs onto a CD for me. I play CDs in my car, but often just listen to one of four radio stations. I listen to Sirius radio at home, switching it around often. Or I will put on one of several music channels on TV.
I just bought a CD: “Blame It On Christmas”, but only 'cause I couldn’t find it to stream anywhere else. It’s a collection of novelty holiday songs.