Meteor 2  
This game is awesome! Its got more playability/modability than most commercial games, and its great for lan parties. Vehicle control is superb, and the game balance is incredible. (so is squishing people with tanks) IThe MP could use a bit of polishing, but its still 100% awesome.

SLUGS 2  
This game is insanely awesome. It's actually the best computer game in existence ever (or very close). 2 Player mode is a must. I just wish it had network for more players and a map editor =)