360 hands down right now. The reason why is because of one aspect, the games. Games make the system. Like the Wii with Wii Sports, games make the console. The 360 has the best line up right now with games like Halo, Gears, Mass Effect, Ninja Gaiden, etc (Yes I know those games have PC ports but we arent talking bout the PC now). Not just that, with announcement of some big name JRPGs like Star Ocean 4, Last Remnant (360 release before ps3), Infinite Undiscovery, and Tales of Vesperia, the 360 is expanding its audience not just here, but overseas.
The Wii is a close second with games like Brawl, Galaxy, Kart, etc. But you have to look ahead and see that there really is nothing coming out right.
As for the PS3, it is hands down the most power. I belive it is only a matter of time before it has the best graphics. The only reason why it isn't doing any better is the games. The PS3 is lacking in this department. The only games its has are Resistance, Motorstorm, Metal Gear Solid. And the future doesn't look too bright either, with only big name games such as Resistance 2, and the Final Fantasies.
That is just my opinion now, along with the fact that the PS3 will be the better of the 3 by the end of this generation when it gets some more games. And sorry for the wall of text, just had to get that off my chest.