Warcraft three is pretty fun. Great storyline. I have recently been playing age of empires, another RTS game, and it's much funner because:
1) You control more units at a time. In WarCraft, a party can only hold twelve. In this it can hold about 35, and you can easilly switch between two assults.
2) Towers, Walls, Castles, an other fortifications. In WC, they are no big deal, and I almost never use siege weapons in that game. In AOE you have to, because the different structures' arrows' rip your soldiers to threads.
3) Customized. Has WAY more troops then any one WarCraft race, and better way's of supporting your economy. For food, you can pick berries from forage bushes, make farms, herd sheep, build fishing ships, hunt dear or wild boar, or barter some at the market. You must also keep up even with your gold and stone.
WC is fun, but sort of shallow. It focus's on the military more then the economy, which is the funnest part.