Bethesda and CD Projekt Red are bastions of greatness in PC gaming.
I played the original MGS on my PS 1 I recall, and quite liked it.
Seriously though, play the Witcher series, 1, 2 and 3, its like Mass Effect, where your choices are imported from one game to the next and can change each game by a startling amount.
They are by far my favourite game series of all time.
Heard Witcher 1 and 2 were not very good and that 3 takes it into Skyrim open world territory?