Every generation of consoles I say to myself, "You know, I'm content now. I've stopped at [last console released], and with the enormous catalog of games to play, I don't think I need to jump back in with a [newest console on the horizon]." Then time goes by, my will crumbles like dried Play-Doh, and I spring for the Next Big Thing.
Last year, I decided on a PS3 over the XBOX 360 for the following reasons:
1) I remain skeptical about the performance of the 360 on the hardware side. Too many horror stories, too many friends with problems, ruined systems and ruined games.
2) It seemed to me like the exclusives on PS3 outweighed the exclusives on 360. See: Heavy Rain, Uncharted series, Metal Gear Solid 4, to name just a few. That trend has continued with (I would argue) stronger dedication to exclusivity on Sony's part, and also, when games aren't exclusive, Sony will oftentimes add PS3-only bonuses to distinguish their versions (see: Kratos from God of War as a playable in Mortal Kombat).
3) Online is free. PSN may not be as good as XBOX Live, but again, no annual subscription fees.
4) Blu-Ray player. My fiance loves Harry Potter and Twilight movies, so this is a big sell in my house.
5) HD game collections. Great for playing those games you missed on the first go-round a generation ago. Intriguing sets for Resident Evil, Metal Gear Solid, and others.
6) PixelJunk Monsters. This was seriously like half the reason I got a PS3. What an addictive, awesome game.
I don't think the PS3 is necessarily better than the XBOX 360, but I do <3 my PS3. I don't have much time to play games, but I love NBA 2K12 and am currently taking my 7'2" afro'd version of myself through my rookie season with the Phoenix Suns. Great stuff.