For me this game fell somewhere between Legend of Grimrock and Legend of Grimrock 2 - not quite as good as the open-world of the second game, but Vaporum's voice acting made it more of an engaging experience than the original Grimrock.

Age of Empires II HD [Steam store page]
One of my favorite RTS - though it does suffer from the rock/paper/scissors syndrome once you know the game well enough. Age of Empires II: Conquerors Edition was a great expansion to the original game, and it's bundled into this HD remaster.

The main benefits are that this runs nicely on high resolution - the original was locked at something like 1024x768, and this also has a few tweaks like allowing higher unit maximums - raised from 200 in the original to 500 in this remaster.

I'm normally not a huge fan of re-releasing old games, but this one was such a classic, and the small tweaks they made improve the experience without ruining the nostalgia.