Quit talking about getting an Xbox and just do it.... I got one and while I only have a few games (Halo, DOA3, Buffy, Project Gotham Racing, Mech Assault, and others) I am glad I did it. I still buy all RTS and FPS games for the PC. But some games are better played with friends and family sitting around a big screen tv. Also, now i can play my relatives and friends that don't have a pc powerful enough to play online games (crappy sound, graphics, and cpu power).
After having played Halo, I'd consider buying an Xbox just to play that one game and would not have a singal regret (yes... Halo is that good!)