Kamikazi Kat

The Halo series has always been known for its lackluster single player. The only time I find it fun is to play it co-op, and even still other games that focus more on single player such as the Half Life series do it much better and offer a much more rewarding experience. Halo 2 and Halo 3's co-op campaign is basically a fancy way to fight bots when you are bored of the online. I'm a huge Halo fan (mostly Halo 2 and 3), its annoying when people judge the game based on the single player alone, or by Halo 1's multiplayer, which can be fun but lacks the better support in the other 2 titles. If you have a 360 and if you are going to get a Halo game, get either Halo 2 or Halo 3 (I'd recommend Halo 3, its online support is much better and its still being updated), and get the game for the online multiplayer.

What I like is Halo 3's multiplayer has tons of variety that appeals to everything from casual gamers to those annoying hardcore players that yell at you. You can either go into ranked matchmaking where it pairs you up with a team based on your global rank and all of that stuff, or you can go into the casual matchmaking playlists where rank isn't tracked and the game variants and maps are much less casual and more focused on casual fun then competition. When people think of online gaming, they think of that hardcore trigger finger that "pwnz all t3h n00bz," while Halo3's multiplayer is designed for both casual and hardcore gamers.

Also, since you have a 360 I'd suggest checking out the new Battlefield games on it. Battlefield: Bad Company is great and has been about for about 2 years, so you can find it for about $20 in most stores. Battlefield 1943 is also good, its somewhat of a sequal to 1942, although it has less maps and weapons (hence the lower price for a game that just came out). Battlefield 1943 might be best because its cheap and you would probably be more familier with it since you played 1942. Both games have destructible environments as well.