I only played about half of the original Halo, I'll probably reinstall it and replay it sometime soon or borrow it from my dad for the Xbox.
Finished Halo 2 a couple nights ago. Thought the game was fun, and I personally enjoyed the story, but I'm a simple man.
My two gripes were the ending, and the aformentioned lack of waypoints. Least they could have done was had a compass type o thing, and have you be told to meet up with so and so south of yer current location. Woulda helped in a few spots. One mission I backtracked about 5 minutes before I realized what I'd done.
I've got a bus trip to go on this weekend, so I'm going to pick up the novels at yonder Barnes and Noble (assuming they have them still) for some time killing.