Advance Wars!!!!
Advance Wars is one of the great essential turn-based strategy games out there along with Civilization and Fire Emblem. Anyone that hasn't played any of these games, should go out and get them. I've beaten all of the Advance Wars games, so I was a bit skeptical about the flash version, but it totally met my standards. The type of strategy that this game favors is exactly my style too, which made it even better. Great game, can't wait for the sequel