Depends where I am, really. While I'm here at uni, I only have my laptop, so my gaming is either on PC or last generation's handhelds. When I'm back home, I use my PS2, Xbox and GameCube more than my PC. And, when I'm travelling, which is fairly often, usually between York and home (that's about a 4 hour round trip) I only ever game using handhelds.
So yeah, a bit of a mix. I guess since I'm currently at uni, PC wins out though.
PS3 though I still play some old school games on my low end laptop. I would play more on my gaming PC but it done broke. I swear PCs just HATE my guts. Now consoles on the other hand that's something else. They rarely fail on me for some reason *shrugs*.
Nothing can beat the allmighty potato!!!
But seriosly, I own a PC and PS3, currently I use the PC more because I have more games for it, but the moment i get a new PS3 game, my PC starts to gather dust.
Despite having a somewhat capable desktop available to me, I game on the 360. It's just a lot easier to boot it up and slap in a disk (or play an XBLA game like Minecraft), and my sensei has honed me well in the way of the controller. Plus, chatting and gaming with pals is a lot simpler when it's through a streamlined and unified system.
Why Minecraft on the 360 though? Because, my gaming sessions on Minecraft get so long, I'd rather have it available on either my laptop or a console over sitting at the desktop. And since my laptop can't walk and chew gum at the same time, the 360 is the only option.
I keep my headset hooked up to the laptop's audio and USB port so I can listen to Youtube though. I also have the PC mic imput plugged in for the rare cases I want to Skype and game, but I almost always use the Xbox LIVE party system. I can even juggle the two at once, and it gets amusing having a pair of simultaneous two-way chats. But that's neither here nor there.
I have pretty decent PC, which i use to enjoy proly 80-85% of my games. I have an 360 and PS3 for exlusive titles only pretty much, and well worth investing. I got my Xbox For Mass Effect(1) and i got my PS3 For Demon Souls/Metal Gear Solid
For me it varies. For example, at the moment, my PS3 is getting a lot of love, with NiGHTS, Disgaea 4 and Tales of Graces f. However before that, my PC was getting most of my attention. So I guess it really depends on what interests me at the moment.
Whatever system the game runs best on. For example the PC port of Sleeping Dogs was solid and we got a free high res texture pack, so I play it on PC. The PC version of Darksiders 2 was pretty poor on the other hand so I prefer to play it on my Xbox. Exclusives I obviously play on whatever system its exclusive too. Generally when it's on all 3 systems it will be PC because I can run it in full high res.
I USED to play console a lot along side with home computers like C64 and Amiga and now Windows 7 98% of the time
Played with NES, Megadrive, PSX, PS2, N-DS...
My last console was the PSP because since then IMHO PS3 and 360 ruined the 'console experience' - know what once was'press power and play'without the need for internet connections.
Nintendo Wii U might be the day saver later because it tries to nothing more that a gaming console now but now.