When thinking back to 80s movies that make me nostalgic, The Monster Squad (1987) is definitely among the top 10. As a kid I loved this movie, and it may be one of the reasons I enjoy movies about the supernatural/paranormal even to this day.
The premise of the movie is that 100 years before the story Van Helsing storms Dracula's castle and tries to use a powerful magical amulet and create a portal to limbo to pull Dracula and his undead minions into the portal. Unfortunately he failed. Dracula was not pulled into the portal but Van Helsing was, so Van Helsing's associates take the amulet to America, far out of reach of Dracula. Fast forward to modern day (1987). A bunch of kids ranging from 12 to 16 have a clubhouse where they meet and discuss monsters and monster movies.
The leader of the club is given a book that his mother found at an estate sale that turns out to be Van Helsing's journal. Unfortunately its in German. They don't think much of it until members of their club start reporting seeing real-life monsters such as the Mummy, Gill Man (creature from the black lagoon), and Frankenstein's monster. They try to tell their parents about everything but understandably they don't believe the kids, so the kids have to take matters into their own hands and find a way to stop their town from being invaded by monsters.
I watched this again around Halloween 2012, and I noticed watching it as a kid and watching it as an adult are two different things. When I watched it as a kid I saw the kids as peers and so when they get picked on, grounded by their parents, and told that monsters don't exist I sided with them and fully backed them on disobeying their parents to go stop the monsters.
As an adult I see it much differently. I see a bunch of kids that, despite meaning well, disobey orders their parents gave them to keep them safe. They sneak out after dark, lie, steal, blackmail, and build weapons to aid them in their fight against the forces of evil. Thank goodness they have parents that care for their safety, especially one of the father's who's a cop.
Still, its a fun movie that has aged surprisingly well and if you haven't seen it since you were a kid I suggest giving it another watch. You would be amazed how differently you see the movie through more experienced eyes. There is a little bit of swearing (they say sh*$) and a few scenes of graphic violence, so it earns its PG-13 rating, so use your judgement on when to let your kids watch it.
Also, for those that have seen the movie and love it, there are a couple websites out there that have interesting artistic theories about the movie, like what the deeper meaning behind Phoebe throwing Frankenstein the Teddy Bear.