Kind of a loaded question really. For as long as there have been comics there have been crappy ones. The 1980s, however, saw the introduction of the direct sale market which made it financially viable for smaller publishers to get their comics out there. Spurred on by the success of Teenage Mutant Ninja Turtles which was a major success story for the small press, scads of comics which a few years earlier would have been lucky to make it into a xeroxed fanzine were popping up in comics stores.
The Stupid Comics section over at misterkitty.org has several interesting sections for lovers of dreadful sequential art, but the 80s section is particularly horrific.
- New Beginning is a particularly incompetent look at nuclear war with a disturbing wish fulfillment angle.
- Sometimes I think I'm the only one who remembers Geriatric Gangrene Ju-Jitsu Gerbils and perhaps that's for the best, but here's a page devoted to the Gerbils and other Ninja Turtle knock-offs.
- The Guardians of Justice and O-Force prove that even if you can afford color printing it isn't an acceptable substitute for a knowledge of perspective and anatomy.
- For several examples of godawful self-published 80s comics, give this a spin.