Nintendo
sorry but the best games of all time and my personal favorites are all older Zelda and Mario and Donkey Kong. I do appreciate various other companies (such as a soft spot for Sega, I really like the Saturn for a lot of its space shooters), and I find the Playstation 1 enjoyable but in the end for me the SNES was the best system ever made with incredible variety and insanely high quality replay value today. I would even say for my tastes that the NES, N64, AND Gamecube are all better than other system in terms of what I am looking for in a game library
I think what sets Nintendo apart for me more than anything is their large amount of whimsical 'adventure' games. There are platformer's and fun story based games on the other systems, but not of the quality of Nintendo
oh, and again Ocarina of Time
