Snow days and TurboGrafx are two of the most awesome things in the world. Together, it's easy to imagine how awesome that day was.
I had a fairly unremarkable library during my first bout with the TG (KC, Pacland, Victory Run, Deep Blue, Parasol Stars, LAII) so my most memorable days were spent with the NES and SMS as a kid. Still, there were two pretty awesome days when I finally got a Duo in '97:
1) The arrival of my "Giant Mail Order from Game Dude." Mailman dropped it off on a snowy Saturday while I happened to have a friend over. I got the 4-in-1 disc, Riot Zone, Valis II, Prince of Persia, Super Air Zonk, Forgotten Worlds, Fighting Street, Exile, and Shadow of the Beast. Unfortunately, they sent me a Reverse Duo Tap instead of a Duo Tap, so we couldn't play two player. Still, it was one of the best weekends ever.
2) My brother's birthday in September '97. We dragged a second TV into the living room and had nine people playing five-player Bomberman '93 on the Duo and four-player Super Bomberman II on the SNES. Controllers were passed back and forth and we played for at least four hours.