Blizzard, probably the most succesful gaming company out right now, released a game called Star Craft.  The game features 3 races, Terran, Protoss, and Zerg, each with their own abilities and units.  The reason  this game is so FUN to play and to deal with is the complete differences  that each race has.  In War2 both races were pretty much a like, but in SC  & BW, each race is so different that all the time, even for the last 3  years, strategies keep coming up all over the place.