As someone who bought darn near EVERY Hero product through the 80's and 90's...
Heroes from the Deep - decent water rules.
Bad News from Dr Drugs - decent High School rules and a good map
Eye for an Eye: Lots of good write-ups...
Olympians - couple good pics I used for Greek Heroes
Mutant File: Good template for Mutant characters which I still use. Other write-up blew chunks though...
EE, Road Kill, High Tech Enemies - All bad! My friends and I would joke about characters in it. "Hey, let's take a snowshovel full of points, chuck them at a piece of paper and see where they stick!" Esp...EE. Went to Origins one year and talked to the Hero booth about it, they were less than pleased, I think they thouhgt they did a GOOD job with it.