If anyone is interested in the history of some of the great games, there was an old show called Game Makers (got renamed to Icons) on G4. https://en.wikipedia.org/wiki/Game_Makers. It covers tons of great classic video games. It was very well done. I wish they sold the dvds. But if you are interested in check em out on Youtube. You won't be disappointed. https://www.youtube.com/playlist?list=PL56FD995C50B57200
Apparently he wrote parts 2 and 3 before getting bored but didn't link them from the original that I could spot - but you can either change the number on the end of the URL or visit http://www.codeofhonor.com/blog/tag/warcraft for proper links to the other two.
He was at HandmadeCon 2015 [1] where they talked about the network code/design in games he had worked on, and various subjects relating to the gaming industry.
This article was referenced at Gamasutra a few days ago, to which his response was that he should blog more. [2]
As another commenter pointed out below, the heyday of RTS games seems to have long passed and the studios that honed the genre to perfection are around no more. Everyone seems to be focused on making the latest Dota clone, so if you want a proper RTS, you'll have to dig into the past.
Games such as Ground Control have a promising concept, but suffer from an extreme lack of polish, which in this case means that you can't save the game during the mission, forcing you to restart and restart and restart over and over and over again until you get bored and uninstall the game.
However, I greatly enjoyed playing Myth and Myth II: Soulblighter. They are both pure tactical games from the 90s, meaning that you don't actually build any structures or produce units in them. Instead, you're given a small detachment (sometimes counting only 1-2 heroes) at the start of the mission and expected to plow through a horde of enemies. The AI is superb and will brutally punish your mistakes.
In some cases, you'll be given grenadier Dwarves and a huge cache of landmines they can carry and set on the ground, ready to be lit and blow everything nearby to smithereens. [0] [1]
The appeal is in the absolute carnage: blood splatters all over the map and the pieces of units fly everywhere, possibly even killing other units in the process. There is an active mod community to this day[2], with unofficial compatibility patches, larger resolution options and UI fixes.
I do not recommend Myth multiplayer, since only the most hardcore players are remaining, meaning that you'll fare poorly if you try competing against teams of people that've been playing for 10+ years consistently.
The Settlers series is very awesome too (aside from that mess of a facebook "game"), and each game in the series has a very different feel to it.
One thing to note, though, is that they're generally much more focused around city planning and resource management than warfare. They're also have a far slower pace than, say, Starcraft does.
The energy has long since moved from RTSes to MOBAs. It's doubtful Blizzard will ever make a Starcraft 3. Pure RTSes are going the way of the point & click adventure game.
I'm sure you probably have, but give League of Legends a try if you haven't. There's still a lot of similarities with RTSes.
I keep a Winows XP box running just to play it and several other games from then and before. I also play the Star Wars spin off, Galactic Battlegrounds, on it. It's AoE II but with SW factions and maps...
I watched a lot of AoE2 on YouTube and Twitch about 6 months ago. It's really fun to watch on the background while doing idle work, and learn the meta and various races. I admit I haven't played the actual game since it was released (great memories for a 10yo to make).
Part 2: http://www.codeofhonor.com/blog/the-making-of-warcraft-part-...
Part 3: http://www.codeofhonor.com/blog/the-making-of-warcraft-part-...