The systems I own or owned or used are a few, I played a lot of arcade games in the 80's (amongst them Donkey Kong, DK jr and the first Mario games, but they never were my favourites), I seldom played on PSOne, but never liked it, and I owned a 4 unchangeable pong-like games console, an Intellivision, a ZX Spectrum, I have played on PC since 1990 and owned my PC's since 1997, I played on Macs too during the first '90s and I have played some Xwindows games since 1991, so my experience is limited to a few platforms.
My list, biased by my current tastes and fading memories of the oldest ones and based on the few I played and loved in each series is:
- Deus Ex
- Thief
- Fallout
- Gothic
- AD&D (first of the franchise I played was on Intellivision, but what makes it climb my list is Planescape: Torment)
- Grand Prix Legends
- Duke Nukem
- Myth
- Heretic - Hexen
- MechWarrior
I wouldn't know where to place Donkey Kong and Mario, after these 10 anyway, but based on which of them I played, DK would come before Mario. And out of my top ten I would rank Half-Life, Unreal, Ultima, MDK and Tomb Raider in this order.