As the title says, list your first game(s) played for a system, plus any awesome memories of said games.... Can be the first game or your first session where you were introduced to the console.
For me, Mario 64 for the N64 was a hallmark moment and a memory i'll not forget. I am positive I'm not alone when saying this game blew my socks off and was the single reason I had to own the console. Also, Super Mario Land for Gameboy was a title i received with the system and continue to play to this day!!
Metal Gear Solid for Playstation was the first game on Sony's platforms that I had really put solid time onto and fell in love with, after playing it at friend's houses, and I remember going into Funco Land way back in the day and trading in what must've been 20 or maybe even 30 SNES games and the system for a PSX and MGS, along with some other games and controllers. The game had that big of an impact, on me at least, to warrant trading in Nintendo for Sony (my then-thought-of rival to the Nintendo brand)