For me a lot of RPG (type) games were awesome at the time (but of course feel badly dated now). BG + BG2, Daggerfall, Morrowind, Oblivion, Torment, Might and Magic 1-8, the original AD&D games such as Eye of the Beholder and the later ones like Dark Sun. TBH the list is almost endless, even of the ones I remember.

So for me of the RPG ones I can remember first time through it would be Morrowind, Dark Sun, Torment, M+M 7, BG, Menzoberrenzan and many, many others lol. It is hard to separate so many games as a lot were great fun to play in their time. It is also harder to rate games nowadays as I mainly play MMORPG's which are a whole different kettle of fish.

A lot easier to do of course is to try and remember the truly bad ones. M + M 9 has to be second on the list with Skyrim on the top. I absolutely hated that game (and still do), in my opinion Bethesda's only failure (I can't rate Redguard though as I never got it to work).

As for studio's / companies I always liked stuff by SSI and tried to get whatever their latest release was, whatever type of game it was. Up until XTC I always enjoyed the Egosoft games, even with all the bugs, but Rebirth killed that and X4 hammered the nails in.

However, being 40 something life isn't about liking things, its about how much you dislike everything, in 21 months I'll be back to being a normal human being again and will have a more level view.