Something probably on amiga but for PC and owned by me I would definately say Unreal.
Unreal on a Cyrix chip and 4mb Matrox Mystique 220 rendered Unreal at about 2 - 10fps max. I could only play the 'darkmatch' because it ran ok - deathmatch in the dark with torches.
My friend (his dad) had a high spec pentium pc with a voodoo gpu and i went to his house to play games instead. I got a voodoo 2, years later and enjoyed Unreal for myself. Massive difference going from a 2d gpu to my first proper 3d gpu, the voodoo 2. 800 x 600 at about 25-30fps was incredible. The very first time a game had 3d lighting, reflections, smoke, water etc etc. Every console game didnt come close...
Then along came Half Life, Starcraft and Thief. Mid - late 90s, a fantastic time for gaming