We have already addressed the game issue, and I am not sure how "pop-ups" affect you gaming experience -you don't get them while you're in a game-. You can play with friends, sometimes more than sixty at a time, on a PC, and you can connect your PC to a surround sound and/or TV. Personally I have a 5.1 stereo system on my PC, and I have a HDTV available if I want a bigger screen. Furthermore, you can mod games on the PC, something that is illegal in the 360.
360!360!