I'm 23, my first game system was atari (hand me down) but honestly, the FIRST one I remember was Super Mario Brothers and Duck Hunt. My mom played Duck hunt for two hours, never losing until she figured out, it kept going, and quit. I'll never forget that.
Also I've owned every nintendo system (NES, SNES, VB, N64, all the GBs, I don't have them all anymore though) except for a game cube. Halo and Xbox have had my attention for a couple of years.