PS3 All the way for me, the games are slowly coming now, aslong as your a patient person it will pay off in the long run, I keep saying this but the PS3's future is a bright one.
Xbox is way too unreliable by a long way (I had one for about 6 months, was great while it lasted) - I wouldn't touch another one of those with bargepole, and the Wii looks fun but i'm a bit of a loner gamer, I think the wii would be more fun if you have your mates over a lot.
PS3 has built in wi-fi and blu-ray which were also big selling points for me, ps2 backwards compatibility, well built, looks great, I'm well happy with mine.
I guess your better off looking at the up-coming and current titles though and seeing which console is getting the games you want.