It's all about Halo
As a kid one of my wishes was a system like the XBOX and a game like Halo.
Quake 3 on the Dreamcast was an awesome game and is ranked a very respectable #17 on this list. The problem with that game is it was 4 players only and some of the bigger maps were left out in 4 player split mode.
When Halo came out I was amazed. It supports up to 16 people on 4 XBOX's, If you play with as many as 8 the smallest screen you will get is a split and not 1/4 of the t.v. The levels are designed better then anything out there too. If this system and game came out when I was 6 I probably would lack social skills.
Halo is XBOX's prized game but there are many good games on this system like Panzer Dragoon Orta (#21 on my list),Crimson Skies and ninja Gaiden.
I dont emulate games and Metal Slug 3 is also on the way so it should be a good one.
The Good-Halo,XBOX live,System link and a lot of the former PS2 exclusives are on this system.
The Bad-I dont think MS has taken advantage of the harddrive like it should. I think Splinter Cell with its 3 new levels is the right Idea and I would like to see more of that.