Duke Nukem 3D
Decided to slap eduke32 on it this time around, it's some fantastic stuff. Haven't played with polymer yet but I'm digging the amount of options we get for everything else. Going to do a play through then I'll start checking out some mods.
Giants: Citizen Kabuto
Playing as the Kabuto right now, it's quite satisfying to be this angry giant who gets larger as it consumes enemies, charging at them, picking them up and throwing them at other enemies, punting them across the map to have them explode on the side of a cliff.The other two races are all sorts of fun as well.
Machinarium
Played the demo a couple times, never got around to buying it until I saw it on GOG, had to get it and I love it now.
Myst
This has been a bit of an experience, interesting puzzles, really intriguing story, and I'm digging the whole concept of the books.
Uru
Started this last night, haven't done too much so far but I'm thinking this is going to be some fun times exploring everything.