I got a Wii and a 360. The Wii is alot more fun to play with friends, whereas the 360 and the PS3 are more toward hardcore gaming. Overll I think that the 360 is the best besides some of the glitches such as the red rings whick suck.
I'll start off by saying that I don't own or have played on either a 360 or a PS3 yet, but I'd only consider a PS3. I can't afford to get both, so I would go with the PS3. Mostly because I went through the PS1 and PS2 so I like the backward compatibility factor. Plus I'm already used to the controls. Excited for GT5 and GTA4!!
I only have the Wii out of all the 7th generation console since there are some games that good for the Wii such as racing games like Mario Kart, fighting games like Super Smash Bros. Brawl and exercise games like DDR: Hottest Party, Wii Sports, and the upcoming Wii Fit.