I owned a PS2, and after a while I wish I had bought the Xbox instead. The Xbox could have up to 4 contollers stock, and it also allowed for LAN play with up to 16 players. To me, the Xbox had more appealing games than the PS2. Halo and Fable were two games I was very interested in trying, but could never do so. Now with Gears of War, Fable 2, and Halo 3 coming, I'm glad I have a Xbox 360 to play them on.
If you're truly into gaming, and strictly gaming, then the Xbox 360 will probably be the best bet. The PS3 will play games at almost the same rate and intensity for about $200 more. The games for Xbox 360 will get better I assure you.
2. Wii
3. PS3