Well, I've emerged from my Day of Halo 2. A lot of people are asking me how I like it, so I'll post here to save my keyboard the wear and tear.
Halo 2 is the best game that has ever been made. I say this even though I have not completed the single-player campaign. The game is almost perfect. It's better than my over-inflated expectations had prepared me for.
Let's start with the bad stuff: Xbox LIVE matches take longer than they should to start. That's it.
Now the good: everything else.
My score? 117 out of a possible 10. Go buy the game, unless you don't have an Xbox. In that case go buy an Xbox and the game.