I've been playing equal parts Quake III Arena, Warsow 0.41 and Eve Online, along with the occasional round of some XBLA game. Fuck yes.
Dark Knight, if you're not a fan of RTS games for their quick pace, you might want to check out Sins of a Solar Empire. It's a mix of the quick pace of Real Time Strategy and the slower 4X genre which is primarily made up of games such as Master of Orion 2 and Civilization 4. Games take several hours, and on some larger configurations battles can take days (thankfully it has multiplayer saving and loading support).
There's also Dawn of War: Dark Crusade, which is probably the closest thing you can get to Starcraft 2 without SC2 actually being out, and quite honestly because of Dawn of War I'm not nearly as excited about Starcraft 2 as I am Dawn of War 2. It's a normal-paced RTS, but it just kicks so much ass that you might not mind.
There's also TASpring, a remake of Total Annihilation in 3D, and it has a ton of neat features, such as realistic weapon trajectories (artillery is awesome in this game), a very unconventional economy, and lots of neat automation tools that take your mind off of some of the more mundane base building tasks and more on kicking your opponents ass.
The simple fact is, though, most people I hear complaining about "Zerg Rushes" and "builds" tend to be people who simply want to play Base Simulator 3000, turtle in their base for an hour or two, and then hit their enemy with some decisive force. Well, at least in their heads that's how they think things will work out, what actually ends up happening is that their opponent either rushes the fuck out of them or their opponent takes every single other expansion on the map in that same time frame and has an even bigger force that dwarfs the turtler's. So they get rolled, ragequit, and complain about RTS's on internet forums, so I can laugh at them.
By the way, in most decent games, there is usually a way to mute disruptive players. Either that, or start dominating them until they ragequit, preferably with some of the tactics listed in this thread, or just search youtube for "myg0t" if you don't mind seeing people use hacks. Record their lamentations and post them on youtube for maximum lulz. Letting yourself get intimidated by a 9 year old on an online game is pretty much the most lol thing ever.