PS2 for library size.
The backwards compatibility is what makes the library size blow the SNES out of the water.
And PC makes me angry when I cannot play old games on a new OS.
Although, if I had been older for it, maybe I would be saying the Colecovision my family had when I was about 5. It had an attachment that allowed us to play Atari games as well, and good times were had, that I vaguely remember.