I bought myself one for my birthday back in December and let me tell you I was also debating whether to get a PS2 or XBox. I do not regret for a minute going with the XBox...
I do not consider myself much of a gamer (you know, your ocasional PC game here and there and stuff) and my last console was 8O an Atari 2600 when I was about 11 or 12...
I was ADDICTED to Halo... I just finished it last week. It is by far THE best game I've ever played on a PC or game console ever.
Also Dead or Alive 3 is pretty awesome (she kicks high!

- if you've seen the commercial)
Well, I hope you enjoy your new Box as much (or more) than I do.
BTW... what's your secret? (I haven't been able to get my wife to play the damn thing... she's not really into electronics at all).