Well not much to add.

Hackers (I love "Cereal killer") (But as this discussion goes can this be called a guilty pleasure any more?)
Willy Wonka and the Chocolate Factory (Gene Wilder) (not sure its a guilty pleasure, but one of my all time favorite movies)
Highlander
And......
The Feebles :)

Zapping into some old japanese Mothra movie some time ago I must admit I was hooked. Some children and a giant mechanical moth saving the world? Sounds silly? At first I stopped there to see how hilariously bad it would get, but then I ended up liking the movie. I would even buy it watch it with my kids.

I actually enjoyed the Dungeon Siege movie (I don't remember the actual title). It WAS ridiculously trashy, it DID make amazing actors perform terribly but heck - I had fun watching it. In a certain way that makes it a better movie than the LotR films.

And I agree on Alone in the Dark not having been THAT bad. It was trashy and silly but it was pretty good as far as horror B-movies go.

japanesse tokutsasu esp sentai ranger, no matter what watching those mecha combine always look great

I don't feel any guilt for any of the movies I like.

TONS of 80's action movies are guilty pleasures for me. The first few off the top of my head would be Cobra, Tango & Cash and Red Heat. Honestly though I love almost any 80's action movie.