Little Green Guys with Guns

For those of you looking for a boardgame-like experience online, I'd recommend Little Green Guys with Guns (at lggwg.com). I'll admit to some potential bias here, because the game's author is my brother, but the game is really fun. It's a play-by-e-mail (PBEM) turn-based tactical combat game. You have a team of little green guys trying who are usually trying to kill the other teams run by other players (although there are some cooperative maps, solo maps, and alliance team maps). Each turn, you plan out moves and attacks for your team, and then they execute your orders. They do this literally - which means your moves and attacks can get messed up if somebody steps in front of you or destroys nearby terrain, often leading to comical and tragic results.

The game is quite mature, having been in development for over five years. There are six different kinds of units with different range, strength, armor, damage, and attack type. There's lots of variety in map design, unit selection and capabilities, and terrain types, and the maps are scriptable, so the user community frequently comes up with new innovations. There are over 130 different maps to play on, and more being created all the time. The player community is open and supportive, with a hotly contested player ranking list. Even better, the game is free to try (donations to support are currently optional, but there may be a small subscription involved in the future).