I've always felt that the Warcraft games had the best missions/scenarios. On the other hand, the Age of Empires games had some pretty solid gameplay. StarCraft had the best Multiplayer though (let's all hope that StarCraft 2 will be as good as the first one).

That said, I have a weak spot for Dune II and the whole Dune setting so..

Dune (1 vote) :D

I'm not a great RTS mind, but I still play C&C: Red Alert occasionally, Tesla Towers FTW!

I really love Dune 2, but my vote goes to Starcraft for .. obvious reasons

my second favorite would be the Anno games, but well they are more real time sims than rt strategy games

Wow! Didn't expect Aga of Empires to get that many votes! o_O

I guess this means Ensemble Studios did something right when they made AoE 2.

I love that package so much. I miss 1999 when it was released (but actually I bought it in January 2000).

Simply a fantastic game.

AOE > Starcraft > C&C > Warcraft

This is a very tough choice, between AoE and Starcraft >_

Starcraft is an awesome game.
I love south koreans since they still play the ORIGINAL starcraft as an official sport.
Theres tournaments and matches still going on in South Korea. xD

I liked Empire Earth a lot. Don't know if it was a series or just one game though. I pretty much have enjoyed every RTS I've played.

Easy choice, STARCRAFT. I'm sure Starcraft II will beat the crap out of the 1st one. Gameplay/Story-wise. Hope it actually comes out this year.