For one reason or another, there are a lot of villains that just didn't make the cut in the 80s. Maybe they missed the decade by a few years - even if their cartoon was a perfect fit for it, like Pirates of Dark Water.
Honestly, this cartoon was better than most of the stuff in the 80s for it's world-building and continuity. It was one of the only cartoons I remember having an overarching story instead of the same conflict every episode. The cast of characters were awesome, including Bloth, that big evil-looking pirate dude up there. If only the cartoon came out earlier...
Speaking of cartoons that came out too early, a few years later one of the greatest cartoons ever came out. Disney's Gargoyles is by far one of the best examples of a cartoon taking itself seriously.
In every regard - the animation, the art style, the cast, the story - this show's quality was the highest around. The story spanned centuries, dipping through time to weave together characters and events in different ways, taking cues from multiple sources, like Greek mythology and Shakespeare's works. Greg Weisman created a cast of characters that covered wide ranges of emotions and beliefs. In doing so, he created possibly the best villain in any kids show: David Xanatos.
This brings up a point I wanted to make about what cartoons and their villains were and were not considered for retrospectives here. You've no doubt noticed Gargoyles above is the first mention of a Disney cartoon, even though the Duck Tales and Chip 'n' Dale's Rescue Rangers were on the air before the end of the decade. I didn't feel that they belonged here since they were adaptations of other material that started long before the 80s. Scrooge McDuck and the chipmunks started out in sorts and comics before ever getting to Saturday morning cartoons. I don't want to do anything here that's adapted from another work.
For this same reason I'm not including a lot of anime dubs. Voltron and Sailor Moon and the like were popular cartoons, but they were adaptations of a Japanese cartoon and not made expressly for American kids like me. Transformers and GI Joe and all the rest might have been animated over there and Transformers might have been adapted from two of their toylines, but the characters and stories were created here.
One last cartoon I wanted to bring up with this is The Real Ghostbusters. Now I freaking loved this cartoon, still do even, but by my own rules above, I couldn't include them here. Granted they did make up a ton of original stuff for the cartoon, and it became a lot bigger than the movies ever were, but it's still an adaptation, which makes me sad. Another reason it doesn't make the cut here is because it didn't have a recurring villain. I know a few of them made more than a single appearance, like Samhain or the Staypuft Marshmallow Man, but it's hardly what you'd call a lead bad guy. Another cartoon I loved watching around the same time, Thundarr the Barbarian, had the same problem. When every episode has a different bad guy, you can't just pick one as a representative of the villains the heroes faced.
I'm coming close to the end of my list of villains for the retrospectives, but I've got enough to fill in for the rest of the year. I've got an idea what to do after that, which I think will be really fun, but until then, keep coming back to look at those villains we loved to hate.