Outside of Busiek's run on Avengers and Iron Man, I can't stomach much past 1993.
Some of my favorite stuff from the late 80's-early 90's:
New Series - New Warriors 1-25, Darkhawk 1-25, GoG 1-25, Quasar 1-50, Silver Surfer 1-82, Doom 2099
Old Series - DeFalco Thor\Thunderstrike, Conway Spectacular Spider-Man\Web of Spider-Man, DeFalco Fantastic Four (at least it was fun!).

There was some decent stuff in the early-mid 90's, but there was also an overwhelming amount of dreck. Trying to complete a collection of this era can be downright depressing sometimes!