1993 for me. In the words of Jason Heine on the All Gen Gamers Podcast. "Someone drop me off in 1993 and leave me the f@*k alone."
Mortal Kombat 2. Virtua Fighter, Samurai Showdown, NBA Jam, Kirby's Adventure, Mario All Stars, Sonic CD, Doom, and mega man x after just a cursory glance at wikipedia.
Plus, you have all the great holiday games from 1992... May be cheating, so I'm not listing them. But I feel like it was mostly downhill after 1993. Not huge drops to where nothing was good ever again. But it was never topped.