I remember a few from various stages of my life (born 1984).
Seeing the demo footage of Sonic 2 in Woolworths and thinking the leaves falling down in Aquatic Ruin zone was so cool and advanced.
The original Sega arcade of Virtua Racing with the moving cars completely blew me away.
I remember my uncle loading up Cannon Fodder on his Amiga, and a REAL song with REAL music came out, along with REAL photos. I was amazed haha.
A few years on I remember a PlayStation demo disc having promo footage of the first Gran Turismo and it looked so real to me, I watched it over and over. The first Driver on PS1 looked absolutely amazing to me also.
I still remember the headache from trying out the Nintendo Virtual boy at Toys R Us for just a few minutes.
Sonic the Hedgehog’s impossibly sparkly invincibility, with the show-off music that sped up to show off that there wasn’t any lag at all from the particle effect graphic. Really everything about Sonic when he first arrived. That’s the best 16 bits ever looked and sounded… Except…
Star Fox. See the other post about Star Fox 64. Star Fox (original) felt the same. Nothing before it looked or played that way. (No offense to Stellar 7’s many previous attempts.)