360 or Wii...
If you're a casual gamer, want to play with the wife / girls / kids / non-gamers -> Wii for sure. The games are fun, intuitive, simple. It appeals to hardcore and casual gamers alike.
But if you want to massage your inner nerd like me, the 360 is the only choice. XBox Live is unbelievable. I find myself drinking and just talking with college buddies while we play the same game, coop, against each other, or completely different games! There are 0 good exclusives for PS3 (and not many on the horizon) - Resistance sucks - don't try selling me on that. 360 has plenty of exclusives - Bioshock, Gears of War, HALO 3 - and several great ones on the horizon - Mass Effect shortly, Fable 2 and Too Human in the long run. Sorry, Metal Gear Solid 4 isn't going to compare and that might also come to 360. As far as games like Grand Theft Auto, Mercenaries 2, Call of Duty, and sports games - they come for both systems and are about the same but you get the superior online experience with 360.
Oh and what about Bluray and PS3's supposed graphical superiority? Well, no one is taking advantage of the overrated Bluray as far as games go - and no one is expected to. And the graphics? The system is so confusing to develop for most 3rd party developers create for the 360 then port it to PS3 - so the graphics are often a push!
Could the PS3 be something down the road? Sure - maybe in a year or 2. And it will be $100-150 cheaper. Meanwhile, the 360 is the better system today and for the forseeable future.
Again, I can't highlight the prominence of the Wii though. I don't own it but if I were back in college and had more time on my hands, I'd certainly have that in addition to the 360. I may even splurge on one just so I can get girls to come over...video games netting girls? It's happening.
God I'm such a nerd. Alright, sorry for the most forceful statements I've made on CP - but this is something I know about ;-)