Here's my order:
1. Price/Availability
2. Controls are the most important.
3. The more reliable console
4. Console/handheld I can download a game save from the internet off of usually has precedence (I have too many games and don't have the time to unlock everything in every game).
5. Who I want my money going to. Do I want Sony, MS, or Nintendo to get a small royalty of my money.
The quieter console has some reasoning behind which version I get at times. If there's a big difference in loading times and lots of slowdown (compared to zero), then that may affect my decision.
Online, whether a particular version looks slightly sharper than another, whether one is slightly brighter, rumble (I keep rumble off on all consoles), etc. make ZERO difference to me. If there's a little bit of slowdown (like MGS2 Substance on Xbox), that won't affect my decision at all. I rarely play online since I'm socially inept afterall.
Last generation, I usually bought the PS2 version, over the Xbox and GC version. PS2 because it was a reliable console, absolutely love the controller, and it was my main console anyway (which I'd take with me if I could only bring one console on vacation. I gotta take a console with me everywhere since I can't go a day without playing a video game). This generation, I will usually go for the PS3 or PS2 version, due to the same reasons I bought the PS2 version last gen, but under some circumstances that might not be the case (like if one platform gets is WAY before another, or if a game was heavily made for the PC, I'd probably go 360). Big reason I buy the PS3 version now is downloadable game saves, which is kind of the same reason I bought the PSP version of some multi-platform games before (like in Outrun 2 Coast to Coast, there's no way I'm going to sit there and unlock everything).
[quote name='Rei no Otaku']
That has changed however. At the moment my 360 is broken, and I've been without one for a couple weeks now. On top of that I might not get it back until August. So I went down to the Gamestop and switched all my 360 preorders to the PS3 version. And from now on I'll be going with the PS3 version for all multiplatform games. I'm not going to have a game like Devil May Cry 4 come out, my console breaks, and I can't play it for a month.[/QUOTE]At the beginning of last gen, I bought Xbox versions of most all multi-platform games. After having lots of issues with my Xbox (took me 20 tries to get games to work), I just got fed up and bought PS2 versions (since it would take one try to work, always). I was originally looking to get the 360 version of games, but once my 360 broke, I said forget it, bought a PS3, and now I will buy the PS3 version. Console realiability is very important to me, more so than getting a version that might be slightly brighter, have maybe 1-2 second faster loading, etc.