I bought a PS3 because I must always have at least one current console in my residence at all times. I had an Xbox because I found an elite for next to nothing at a used bookstore, but sold it shortly after it came back from the RROD repairs. The PS3 was for bluray and the fact that I am not fond of Microsoft as a whole anymore.
I have bought two Gamecubes in the last 5 years, because of the Zelda collection and Super Mario Sunsine. Anything older than that I find 'other' means to play.
There is something incredibly satisfying about getting to play games on your couch on a huge TV, but the graphics definitely don't compete with anything midrange and up. I rebought Arkham City on the PC just to experience the pixel wonders. If consoles looked and ran as well as games on the PC, I would switch in a heartbeat. Just cant' beat sprawling out on my couch with my modestly large TV.