Earthseige 2
Tribes 2
Earthseige 1 wasn't nearly as good, Earthseige 3 ended up becoming Starsiege, an online computer game and one I just wasn't very good at. These games were also the precursor Tribes series, an online computer game that I was pretty freakin' good at. Tribes 1 was a lot of fun but 2 just blew the damn thing out of the water. Tribes 3, however, suffered the same fate as the third Earthseige game, in my opinion, and just wasn't nearly as good as its predecessors.
Earthseige 2 was an amazingly fun mech game and, while it followed a very linear and not too original storyline, the missions you went on were so psychotic, engrossing, challenging and downright fun that they made you care. Terrific weapons (Plasma Cannon! ELF!) pretty good AI on both enemies and allies and a lot of fun mission based objectives you had to take care.
Tribes 2 is one of the most fun experiences I've ever had in online play. Once you got the hang of the jetpack and once you figured out the maps, you could pull off the most insane stunts. I've never had more fun playing capture the flag than this. Such an immersive game, too. You could destroy the electricity generators in enemy bases, preventing any enemy characters from having anything but the weapons, armor and accessories you spawned with. There were vehicles, there were deployable mines and turrets, you could purchase accessories such as the energy pack (use your jetpack longer), repair pack (repair your generators, turrets, etc), shield packs (take more damage). A team had to communicate well and everybody had to play a role, you couldn't just all storm the other team and expect to accomplish anything. Amazing game.