I miss 90s NBA ... NBA on NBC, Jordan, Shaq/Penny, Ewing's Knicks, Olajuwon, etc.
90s music was way, way better. I miss music videos being a thing.
I miss life before 9/11. Everything was much better then, ever since then it feels like a dark cloud has descended down, the 90s with Clinton were a lot more optimistic and the world felt a lot safer even though there were still some terrible things going around the world.
I do miss 90s Nintendo. They're still great today, but I think they were firing on higher cylinders in the 90s. Virtually every year of the 90s, Nintendo had a GOTY or GOTY candidate (1990 - Mario 3, 1991 - Mario World, 1992 - Mario Kart, 1993 - Star Fox, 1994 - DKC, 1995 - Yoshi's Island, 1996 - Mario 64, 1997 - GoldenEye, 1998 - Zelda: OoT).
I miss arcades and Sega.
I miss 90s boxing (Mike Tyson, Evander Holyfield, etc.), when boxing fights were like a big event. I don't really care much for UFC.
I miss the early internet, when it was just fun to go into random chat rooms and chat with people and that was like some super cool thing, lol.
I miss 90s summer blockbusters that didn't have superheroes in them
I miss Seinfeld.