I own the new Warcraft III series from Blizzard, and other true 3D games like Emperor: Battle for Dune, from Westwood/EA games.  I say this because some of the older RTS games like Westwood's Command and Conquer series, Dune 2000, Blizzards own Warcraft II, and other games date badly.  You can see this in terms of the control problems, blocky graphics, clunky path finding, and (if you play online) nearly non-existent fan base.