Well, since I've already played just about every level of Halo half a dozen times, including playing the complete game through at least once on Easy, Normal, and Legendary difficulty settings, I've been using a few spare moments (usually just before bed) to look at some of the other Xbox games.
Starfighter wasn't very pretty or playable-- the controls seemed completely counter-intuitive, and it wasn't possible for me to get into playing.
DOA3 is extremely pretty, but only holds my attention for a few moments. Fighting games aren't really my thing, and the "story" as such isn't detailed enough to really hold one's interest.
NHL Hitz, while a bit gimmicky, is a lot of fun to play. You can only play 3x3 plus goaltenders, and most of the rules of hockey are missing-- there's no offsides, no penalties, no two-line pass... but it is fun to play.
I took Boston all the way to the Stanley Cup, then started playing a custom team-- kind of a kick to see such realistic gameplay with names like "Vesey" and "Gravelle" on the back of the jerseys :)
It was fine until the team I was up against was the "Egypt Pharaohs" who played in a rink that looked like the Temple of Karnak. I wouldn't have minded so much, but playing hockey in the sand with a blue scarab beetle isn't as much fun as it sounds, especially against nine foot tall players.
I won anyway.