Being honest, games like Half-Life 2, Halo 2 and others (too many to list) are great games, each one fighting for Number 1 spot but the best game is Warcraft III, Ok, now your going "OMGWTFBBQ!" its understandable, but why its No.1 cos i bought it 2003, and i still play it, 2006. Why? one word. Battle.Net not just playing the normal game, but Warcarft III Comes with a Editor and basically you can make your OWN game and play it on battle.net with m8s, That is great, i mean i can go from playing a game "Dawn Of The Dead" which is basically, some one has made a game (almost like a mod) replaced the textures and models with Human marines and replaced the enemies to be Zombies and you have different classes and shit, its great...
So if you can, you should buy WarCraft III Today, It is literally 1,00000 games in One..
In my opinion C&C Generals & expansion Zero Hour is one of the best rts games out there today slightly much better than Warcraft III, the only thing i do not like about Blizzard's game is that they put limitations on unit production so its definately not easy to outnumber your enemies. I just wish they release a new Star Craft sequel
In my opinion it could have been better if they did not included that mind control ability for the dark archon. it perfectly ruins the game balance, i mean think of it, with this ability all protoss players were now able to build units and structures of other factions while both Terran and Zerg cannot