Well I can't remember NES and the SNES gen as I was too young to buy them myself. I guess earliest would be N64, Dreamcast, GameCube, Xbox, Xbox 360, and PS3 as I purchased all of those at launch. The latest would be PS1 & PS2, I bought both about 2yrs after launch.
Love the product, not the company. They love your money, not you.
-TheRealMafoo