I started being a Nintendo fan because my best friend had a NES and SNES and Gameboy and I wanted to copy everything that he did. Also, I decided to pick up a Gamegear at Funcoland at some point, and was extremely disgusted by the fact that it sucked up its 6 batteries in like 1 hour. So I 'returned it' meaning, they forced me to sell it back to them at 1/8 of what I paid them for it. After that, I never bought any other system besides Nintendo until my 360 Elite.
I have owned the original Game Boy (Classic Gray), Game Boy Pocket (Black), Game Boy Color (Teal), Game Boy Advance (Arctic White), SNES (1st and 2nd versions), N64 (Black), GCN (Indigo), and Wii (White). I know people have more impressive collections than that, but I'm proud of it :D.
Most defining games of my childhood were Pokemon Red Version and Chrono Trigger.