My mroommate bought a Wii for Wii Sports and I got zelda for it, because I heard Zelda is cool.

NES. Super Mario Bros w/ Duck Hunt.

...that's when my journey all started.

Back when I was 3 I played Mario World for the first time, good times!

Super Mario Bros in the NES. I used to watch my sister play it until I was finally old enough to play it myself. Then my addiction began...
Also Duck Hunt and that fucking dog. 

Definitely watching my older brother play NES games. Then I tried my best with Super Mario Bros., Duck Hunt, Bubble Bobble, Kung Fu, Legend of Kage, etc.

I went over to a friend's house and at first he had Super Mario Bros. and a basketball game that he used a glitch on to be unstoppable.

I absolutely did not care about either one.

Then we started playing other games, like Nobunga's Ambition, which was a blast. We'd seriously plan out our next Ambition play-dates and we got super competitive about it. I had to have one after that and started saving Christmas/Birthday money (with my mom making up the difference). Contra was another fun game he ended up with.

After I got one, I tried to get into Mario and Duck Hunt, because games were so expensive, but I just could not. Luckily, the local rental store would sell old games and I got some great ones that way, like Double Dragon II and Punch Out.

Ended up finding Final Fantasy in the bargain bin, which ended up as the highlight of the NES for me.

My first Nintendo experience was Donkey Kong in the arcades. After that it was Zelda and Metroid on NES.

Pokémon Red or Super Mario World.

I had Sega consoles only, up until the their demise, then I turned to Nintendo and got a Gamecube. I had played the odd Mario game and some N64 stuff on friends consoles, but my first hands on proper game from Nintendo is my avatar picture. Its Wave Race Blue Storm that introduced me to the charms of Nintendo, after Sunshine, Double Dash and Windwaker I was completely hooked on Nintendo and have been ever since.

My first Nintendo game was Pokemon Platinum in 2009.