The Monster Squad is a movie I had heard about numerous times before I finally watched it, so I'm not really sure who out there is left for me to recommend it to. So, if you're even further behind than myself, this is the movie that's often considered The Goonies with monsters.
The plot is that a group of young boys who are obsessed with monsters realize they're the world's best hope at defeating the combined forces of classic horror villains like Dracula, Frankenstein and the mummy. The movie is exceptional because it draws from a genuine love of horror movies, and so even if somebody doesn't know this subject matter particularly well they can still relate to the film through an understanding of what it's like to be a fan of anything. The movie is also funny and has great gags and one-liners throughout it.
The Monster Squad does feel dated at points. There's homophobia, a plot line involving figuring out if a girl is a virgin and a character who is almost only referred to by the nickname Fat Kid. There's also a scene where one of the boys makes his own silver bullets during shop class, which I'm guessing wouldn't happen in a modern movie. It's still a very charming movie though. As far as it being horror, there are some slightly brutal scenes toward the end and some moments of dark humor. I'd recommend checking it out if you love classic horror or if you want to put on a Halloween movie for some kids.