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.
My problem with the game is it has almost zero challenge until the boss fight. It makes it hard to tell if I’m scaling up to it appropriately.
It is quite fun though.
I can't beat it on normal in like, hundreds of hours of trying. :sadness:
I only have a few dozen in it because the boss is just anti fun. I’ve heard there’s a really good mod that rebalances everything, might try that eventually.