Played my first game on a dedicated Pong console but my first transformative gaming experience was either Ultima III, Archon or Starflight. Those games were on IBM DOS machines with only 4/16 colors and a floppy drive. In the arcades it was Dragon Slayer and a little later the original Street Fighter.
The Super Pong IV standalone system and the Atari 2600 were hand me downs from my older siblings which got me into playing games as a kid. From there it went NES > Sega (Genesis, CD, 32x, Saturn, & Dreamcast) > PC > Xbox (original, 360, One, seriesX).
As for my all time favorite game that I can still pick up and play for hours even today; Flashback the Quest for Identity on the Sega Genesis.
Gaming is life.