Tough one.  I'd say maybe the following:

Asm v.5 & 7 are up there (and I'm not even a huge Spidey fan)
FF v.4-5
Ux v.3-5
Dr. Strange v.5
Thor v.7
Warlock v.2

Some other great volumes include Asm v.1-2, FF v.6, Thor v.3-6, Dr. Strange v.1-2, Nick Fury v.2.

Oddly, my two favorite titles didn't make the cut (Avengers & Hulk).  Mostly mediocre writing during that period.