This one was recommended by Netflix: The Monster Squad. I'd never heard of it, but it sounded cute.
A group of junior highschool kids in a small town have a monster club, and it turns out that Dracula, the Wolfman, Frankenstein's monster, the Mummy and the Gillman have moved into town. They are planning to bring the End of the World, and only the kids can stop them.
Made in 1987, this movie has plenty of that cute 80's-style kids being nasty stuff - cursing, talking about sex, sneaking cigs, and so on. It's still a kids movie (pre-teen, I guess), but adults can enjoy it too.
We did enjoy it, but it didn't become an instant favorite. I understand it's kind of a cult movie. I haven't seen The Goonies or The Explorers, but I kind of bet they are better than this.