Which are the best games you've ever played, and why?

[endimion]

on PC

prince of persia on dos
alone in the dark the first one
ultima online
marathon
duke nukem
FF7
worms
GTA old one
carmagedon


on old consoles

mario 1 to 3
Sonic
alex kid
kick off
street fighter
mortal kombat
desert strike
tetris
duck hunt
track'n field


recent gen

Halo
forza
kotor