While these may not be top quality films, they are may favorites because I can sit down and enjoy them any time even I've seen them countless times already.

In no particular order:

Spaceballs
The Princess Bride
Robin Hood: Men In Tights
The Matrix (just the first one)
The original Star Wars Trilogy
Star Trek 1, 2, and 4.
Blazing Saddles
Monty Python and the Holy Grail
Kung Pow
Transformers The Movie (the cartoon one from the 80's not this CG garbage)
Conan The Destroyer
Red Sonja
Beastmaster
Superman 1 and 2
The Last Starfighter
Goonies
The first 3 Indiana Jones movies.
Galaxy Quest
Aliens
The Abyss
The LOTR trilogy

That's all I can think of right now.