Considering that the Commandos games are purely tactical, is there even another WW2 RTS on GOG?

Yes, there really isn't anything that Sacrifice can be compared to. It's unique, and it's excellent.

Don't forget that Command & Conquer classics (Tiberian Dawn, Red Alert, Tiberian Sun) are now freeware.

Ground Control 2 is an awesome game!

Why didn't anyone mention Praetorians? I really like the way it mixes between tactics and RTS without being hardcore or "overrun the enemy with masses of troops".

Quit trolling. If you don't know what your talking about then shut it. There are plenty of GoG games that work online. You can't tell everyone this because you only bought from one series.

Okay, what did Steam pay you? And WHY is your grammar so horrible? Did you read 'Hoocked on Ponifcs' while in school?

If you mean 'online activity' as in 'active multiplayer community', then yes...most old RTS games (probably except Starcraft) don't have that anymore, no matter where you buy it from.

Lol, good to see a fellow MST3K fan on here.
As for the RTS, I could care less about multiplayer, i'm just into the single player. Alot of great suggestion everyone, but it seems like some of these games have balancing, AI and pacing issues from the reviews i've read. Sounds like I need to download a crapload of demos and see for myself. I'll be right back in about oh....... hours? lol.

At least they're relatively easily found.

Best RTS: SACRIFICE (weird and cool!)
Best RTT: Ground Control (just pure awesomeness!)

I recommend Stronghold: Crusader. There's not really a story, but the crusader is trail is pretty fun. Its basically a bunch of challenges on different maps against different flavors of AI. Basically, each one has a different strategy, and its really fun to find the best ways to beat them.
I also highly recommend Commandos 2. It doesn't have resource management or anything, but it is an incredibly fun real time tactics game. Its a game that rewards creative thinking, so I really think its high class.