AOE 2 was a ton of fun, still throw that in sometimes, I play it practically like a sim city game laying out my empire and don't know anything about competitive multiplayer at all, even against harder AI. There was a Star Wars RTS game that was pretty much modelled after AOE2 at some point as well.

I haven't really played a lot of other RTS games, I liked Empire Earth for a while (AOE designer's follow up) but that had certain flaws but was fun for what it was.

Starcraft has a certain pace and style that's unique to it that I've never felt other games replicated which is why it feels kind of timeless in a way.