Rome Total War FTW.
Best RTS I played a while.

Company of Heroes is a truly epic game.

Starcraft sets the standard for balance.

Yes, it is. Get it.

Yes, Starcraft is balanced, but dull. I don't really see the point of playing an RTS when there is only about one applicable strategy.

...And I prefer Red Alert 2 to Starcraft because Red Alert 2 is FUN.

I liked Red Alert 2 because of it's sheer cheesiness - Tesla troopers and Radiation troopers, crazy Ivans, trained dolphins and in the expansion packs, a UFO and a big brain in a jar that controls stuff! The FMVs were pretty much the icing on the cake in terms of cheesiness - they really went the whole hog in terms of the dress code and so on.

But yeah, massed prism tanks did it for me - nothing like rolling in 20 elite tanks and stomping the snot bubbles out of a base in 20 seconds flat.

Prism tanks are definitely one of my favorite units from that. Their range beats out most everything that would otherwise have a chance against them and when they're fully promoted, the laser bouncing just gets insane. And no, Starcraft's strategies don't really appeal to me on a tactical basis. On the surface, I was quite interested in the rather simple strategies introduced early on - firebats in front and marines in back - but that never really progressed to a point where I felt that strategy played any great part in the sense that I best understand it. RA2 was less balanced (mostly fixed in the quite excellent expansion), but nevertheless held charm and more general fun in playing, and I felt that it provided a better single-player experience overall.

Even though most RTS games are losing their appeal to me, Company of Heroes impressed me quite a bit. Especially since it has more realistic physics than many new FPS games. (RTS + ragdolls = win) Also, I haven't yet tried SupCom, and it looks pretty good.
C&C3 disappointed me. Especially the Scrin-dominated online multi.
Red Alert 2 is raep.
Total war series I like (at least Rome and after), but they just get boring after a while IMO.

Edit: Mispel

I'm a big Ground Control 2 fan, love it, still wish the online community wasn't so small...but, I suppose they've moved onto World in Conflict.

Very big Homeworld fan, too. Lovely game. Such epic soundtrack and vast feeling, all wrapped up in such beautiful design aesthetic. Awesome.

As far as what the "best" RTS consists of, I guess that is a far more subjective concept. Some people like base-building, others perhaps real-time tactics (such as the aforementioned Ground Control and Company of Heroes).

Whatever people reckon, it's a damn awesome genre.

Command and conquer is great, I really enjoyed the Red Alert 3 beta and I'm waiting eagerly for its release (some say its a disappointment but I like it).

Supreme commander is epic, the huge battles and stuff make it awesome.

Warhammer 40k: Dawn of War SOULSTORM
the necrons will kill all other games maby

Huh?Polish immigrants? Maybe?
Anyway, I'm not a big fan of the genre, but RA3 might just make me one. Those Tesla coils look hella cool.
Although I used to love AOE back in the day.

Shoot I can't think, maybe it is real time, and maybe it is a strategy game.

Company of Heroes is a personal favorite of mine.
Lots of strategy involved and victories are always very satisfying, especially against a top 100 ladder player.

I also, can report massive sticky explosions for Company Of Heroes, though the Opposing Fronts expansion ♥♥♥♥ the balance a bit.

What's your Relic Online name? We should do 2v2 AT sometime.

Well, I don't play RTS games as often, but if I had to pick a couple favs, I'd have to say Homeworld 1 & 2, Warcraft III, and Warhammer 40k: Dawn of War.