For me, I'd have to say Old School X-COM (UFO Defense, TFTD, X-COM Apocalypse to an extent). I love them in a way that I just do not enjoy NewCOM, but the interface was quite possibly based on the recovered works of a 13th century scribe, and is very difficult to get used to for an unfamiliar player.
I was convinced to play dark messiah a while back and it was the best time in a fantasy game in a while. I want to live in a world where games took after that rather than skyrim style open worlds.
Rope arrows make exploring 3D environments so much fun, and using physics to dispatch foes is a treat.
It's amazing that "kick enemies into spikes" was added late in development there.