Halo and Halo 2

Well, I'm sure these games have been reviewed and run in the ground, but I don't care. I'll do it anyway. Both these games are similar. Halo 2 brings in some new things, such as locations, characters, weapons and the best of all, online multiplayer.
When I first got my Xbox, I played Halo. It's a fairly short game, compared to other ones, but it's a great game. I played it for a while until I got to The Flood areas. I just don't like playing those guys. It wasn't a whole lot of fun for me. It's a game you can't save when you want, you'll have check points you do, so it's not a pick up and play game for 5 or 10 minutes and then put it down, but they check points are fairly close.
Halo 2 I played for the first 3 or sor levels, then The Flood came and I stopped. Damn flood. Multiplayer is the best aspect of the game. I've spent countless hours playing with friends online in team battles and rumble pits. It never loses it's fun. It might get repeatitive after a while, but you just change the options and you'll have a whole new game.
All in all, Halo 2 would be better worth your money. If you have Xbox Live, you'll spend most your time on there anyway. The single player games are extremely similar and they both have system link multiplayer, but you'll get more bang for your buck with number 2.