Maniac Mansion/YMMV


 * Awesome Music: Dave's Theme (The Boys Are Still Back).
 * Character Tiers: Yes, some characters really are easier to solve puzzles with than others. In a nutshell: Bernard is top-tier because he has multiple skills and very few Unwinnable situations. Jeff (and Dave) are the lowest-tier because they are the only ones that cannot bypass the  by themselves.
 * Ear Worm: The NES version's soundtrack sports a number of them.
 * Good Bad Bugs: In the NES version, "dead" characters can be brought back into the game (sort of) by furiously clicking in the peripheral areas of the front yard. The catch: you're invisible, not that anyone in the game seems to notice (or care).
 * Also in the NES version you can completely bypass the sub-quest of fixing the electricity to find the PIN to get into Fred's lab.
 * Nightmare Fuel: For the sake of your mental health, don't listen to what Nurse Edna says when she catches a male character. And whatever you do, for the love of God don't play the Tentacle Mating Calls record around the Green Tentacle.
 * Unwinnable by Insanity: Although it was possible to put the game in an unwinnable state, unlike most other games at the time you could generally only do this if you either sucked really badly or were a sadist who enjoyed watching the player characters suffer. Here are some character-specific ones:
 * Bernard: Call the Meteor Police too many times, and they won't come anymore.
 * Syd/Razor: Send in anything that's not Green Tentacle's demo tape, rip the envelope, or fail to get the stamps off the package before Ed receives it.
 * Wendy: Send in anything that's not the corrected manuscript, or cause any mail-related mishaps listed above.
 * Michael: Don't get the package in time before Ed gets it first, and the roll of film won't appear.
 * Jeff: Useful kid dies before completing their required tasks.
 * Wangst: The Green Tentacle. "Oh, I'm so depressed!"