Maniac Mansion (1987, C64)

Maniac Mansion is a point-and-click adventure originally developed by Lucafilm Games (later LucasArts). The game also came out for Apple II, and was later ported to PC, Atari ST and Amiga. It was ported twice to the NES.
Maniac Mansion is a parody of cheesy teenager horror films where teenagers stumble around some remote, spooky location and fall prey to monsters or villains. The story begins with a meteorite coming down near a mansion 20 years earlier. The mansion is inhabited by Dr. Fred and his family. Ever since the incident, there have rumours of strange things going on at the mansion. Now Sandy, a local teenager, has disappeared. Her boyfriend Dave is convinced that she was kidnapped by Dr. Fred, so he sets out with two of his friends to rescue Sandy.
The game lets you control a party of three characters. Dave will always be part of the group, but you can choose two other characters out of six. Depending on your choice, some puzzles have to be solved differently, as every character has different abilities. For example, Bernard can repair certain things, but he is to afraid to do several other tasks. You can switch between characters at any time, and some puzzles also require more than one character.