Well hello everyone, my name's Jake and I have a quick question for the classy community of GOG. I've been a hardcore PC gamer for some time now, though I've ignored an important factor in PC gaming itself: RTS games. I've played games throughout the years, RPGs and Turn-Based Strategies to name a few. Browsing through my collection of games, I realized that I'd never actually played a RTS game before, and need advice. I'm a quick learner (I taught myself Visual Basic) and am looking for a good RTS to start out with. Is Starcraft good to start with, or something newer?
Thanks,
Jake

Total Annihilation, Star Craft, Dune 2 (or 2000), Command and Conquer 1 or Red Alert 1. Those are the ones I would "start" with.

Starcraft
Warcraft 3
Company of Heroes
That is pretty much it. Easy to learn, hard to master games. :)

Starcraft and Warcraft are good, Command and Conquer is good and free(at least the first 3 are)
I'd buy Starcraft or Warcraft III to start off if you have the chance.

As far as Starcraft and Warcraft go, do NOT go online. You will get schooled so fast that your head will spin.
The 'craft and C&C games are far too much about rushing, which I don't find fun whatsoever.
Company of Heroes and Dawn of War are pretty cool.
Rise of Nations (or Empire Earth) is you want a real time version of Civilization.
Or try the Total War series if you want some turn based/real time combat hybrid. Not your "typical" RTS, but tactics can often see you through rather than numbers.

If you're thinking about buying Starcraft or Warcraft 3 from Amazon, let me know. :p

This is a tad difficult to answer, since I've been playing RTS games since I was 7 or so, but I'll try. StarCraft is a bit dated by now - there's a lot of micro involved, and as such the learning curve might be a bit steep. It's still a great game, though, and you can't really go wrong with it.
You might want to try WarCraft 3 (and its expansion, of course) - it, unlike StarCraft, features a lot of little things which have become a standard for the genre, and while there's still a lot of micro involved - despite the addition of auto-cast for certain tedious spells - the scale is smaller than StarCraft's, and should be more manageable.
The first Dawn of War is also a good starting point. While not as different and/or innovative as I'd wished it would be, the squad system nevertheless cuts out a lot of tedious micromanaging, although there will still be a lot going on.
DoW2 is a very different game - it's more of a real time tactical game, and of a much smaller scale. Interestingly, DoW2 can be said to venture into action game territory - there's a lot going on, but as you rarely control more than a handful of squads, each being highly specialized and capable of devastating the rock to their paper in moments, you never really get overwhelmed, and so it often comes down to fast decisions.
I'll also add Supreme Commander while I'm at it. Huge scale, brings computers to its knees, and some very clever solutions to reducing in-game chores. Other than that, however, it's a fairly traditional RTS, and you're probably better off with a Blizzard game to start with if you want to ease yourself into the genre.
The early C&C games are intuitive enough, but I'm not sure how difficult the campaigns are. You should probably stay clear of Sacrifice, as it controls like an RTS but features a locked camera that can take some getting used to. And, of course, for "unusual" there's Hostile Waters: Antaeus Rising, which is an action/strategy hybrid.

Only online are they about rushing, and I don't think there are any RTSs to be learned initially by playing competitively against random people. Starcraft and Warcraft both have campaigns that slowly introduce you to new units, as does Dawn of War. But I found DoW's learning curve to be a bit steeper.

Warcraft 3 just oozes quality, from gameplay to how well Blizzard can spin a story in the single player campaign, the same goes for Starcraft. The original DOW games are excellent rts games too. Warlords 3 you can pick up on GOG, another great game that will keep you busy for a long time.

Total annihilation is pretty easy to get into and is the best RTS in my opinion but i dont know if there are many people playing it as i lost my copy. Starcraft is more difficult and the skirmish A.I is pretty hard at first but the campaigns good. Company of Heroes has a good campaign and the people playing online are usually pretty cool and will give you tips and advice if your new instead of insulting you and swiftly crushing you.

If you're a beginner, I would highly recommend Dawn of War 2. As a previous poster said, its not a traditional rts like Starcraft or Total Annihilation, but i think its a really great game to use to improve your micromanagement (something thats really important in rts). The campaign is fun, and the multiplayer community is alive and competitive.
Warcraft 3 is also pretty good, though. Never really got into the multiplayer myself (just screwed around on custom maps), but the singleplayer campaign has a decent story. I'd stay away from Starcraft, despite how many people still praise it, the gameplay is quite outdated. Newer games like DoW2 (and the first one) are much more streamlined and player-friendly.

What exactly is so dated about Starcraft's gameplay? :)

Soldiers: Heroes of WW2 once you get really good. Also sold on GOG.

The Command & Conquer series is usually a good introductory RTS. But a lot of the foundations it laid down have since been surpassed and C&C simply hasn't moved with the times. A victim of its own success maybe.
One of the best examples of an RTS to date is Company of Heroes. You can even pick up the anthology version very cheap. It's an exceptional game in so many ways. Both the campaign and multiplayer are outstanding.
The Total War games offer both a grand strategy turn based world map and large scale tactical battles. Thus not an RTS per se, but not to be missed regardless. I'd recommend Medieval 2, Empire or Napoleon.
Probably the purest RTS out there is Supreme Commander (or its spiritual predecessor Total Annihilation). The amount of strategic potential in that game knows no bounds. Tons of unit types and they all have a purpose. It's just a matter of knowing when and how to use them. It is a bit dryer than most RTS as a result though.

Dawn of War is Relic's successful precursor to Company of Heroes. It's subsequently a lot simpler and might serve as a better introductory game. Again, the Anthology is cheap as chips.
I've also heard great things about Men of War, but I've yet to try it.

I'd go for C&C as well, its a fairly gentle entry to the genre which makes sense since it was one of the primary building blocks of the genre itself.
Its also free http://www.commandandconquer.com/news/your-command-conquer-freeware-awaits