I've only ever had a Wii and a PS3, of the three. I've played on an Xbox 360 though. It's just before my PS3 most of my friends I wanted to game with had PS3s so I figured why not join them.
Not to mention I prefer the PS3-only games over 360-only games. I mean, LittleBigPlanet? Journey? Flower? Those games are fan-fking-tastic. And if I didn't have a PS3 I never would have been able to experience them.
Don't get me wrong, I thnk 360s are good as well, but for what I play and who I play with, a PS3 is the one for me.
Even though I have all the consoles possible ;3 I will always choose the Xbox 360... It has the best games that I prefer and even though you pay to go online, I know that I've paid to game safely ;D Plus it is the only Console that I dont get booted off because of the internet (: and it has HALO (:
I've never owned or played PS3, but I like XBOX 360. I liked Wii when it first came out because it was cool, but now I only play it when I am really really bored because there are not very many good games. = Wii sports is basically all I play on it anymore.
Even though I'm a Nintendo fan I gotta say the 360 is the console of this gen. Its online and friend systems are great, the menus are easy enough to navigate, and it's got a decent range of good (if all quite similar) titles... Got high hopes for WiiU to help Nintendo make a comeback, most Wii games weren't quite up to snuff (relying too heavily on gimmicky technology that isn't far enough along yet to be practical for most games... though it worked in a few, like Metroid Prime 3). If games on the WiiU are designed anything like the games on the Gamecube were designed, I think I'll be happy. Nintendo doesn't need to try to be Xbox in order to be good (@ all the random-a** third party titles coming to WiiU like Batman and Mass Effect...)
The Wii is pretty old and doesn't have alot of good games. I'm not saying this, because I'm just a PS3 person, but the PS3 is more classic, has better games, and free internet. XBox 360 is alright I guess.
Don't forget terrible account information security.