I haven't played an RTS in a long time. I love the fantasy genre and always liked the Warcraft series. I've been waiting for Blizzard to make Warcraft 4 forever but they're still milking their ca$h cow....World of Warcraft.
The way I've always played those games though: Completely wipe out nature by stripping all the mines and clearing all of the forests and horde as many resources as possible. The fun thing about the games is sometimes you find some secret after clearing a really big, annoying forest.