PS3. It established great, new franchises (Uncharted, InFamous, LBP, Resistance), It expanded on previous ones (God of War, PSABR, Rachet and Clank, Killzone) and gave me everything else in between and it brought graphics, presentation and story telling to a whole new level. Not to mention it kicked up the popular Play, Create, Share "Genre" giving lots of value to games. I could not ask for more. Well, maybe that i didn't have to replace it up to multiple times. 4 years and still kicking. What else? Free online play and a built in blu-ray player. What more can I ask for really?
I played a good amount of Wii games and i recently bought one used and Xenoblade, which i plan to finish soon so that would be my second. I also want to play the last story.
I played Halo: Reach and Dance central like...2 years ago at a friend's house. Haven't touched a 360 since then.