High Spirits is one of my favorites. For those who've never heard of it. Peter O'Toole is Peter Plunkett, who owns a castle in Ireland that's in danger of foreclosure. He decides to claim that the place is haunted to bring in tourists. But the place really is haunted, you see. So when the fake ghosts are a complete flop, the real ones step in on All Hallows' Eve...
It is a terribly goofy movie. My favorite scene involves a whistling fish.
Also full of great quotes-
Mrs. Plunkett: Good morning, darling!
Plunkett Senior: Good morning dear! Well, our son is an idiot!
Mrs. Plunkett: We've known that for years, haven't we, darling?
Plunkett Senior: Well, this time he has surpassed himself. The ghosts are furious!
Mrs. Plunkett: Why?
Plunkett Senior: Well, they've heard that that Jim Brogan fellow is going to move the castle to Malibu!
Mrs. Plunkett: Oh, how nice! All that sunshine and all those movie stars!
Plunkett Senior: No respectable ghost would live in California!
(ETA - Mrs. Plunkett is alive and elderly. Plunkett Senior is actually dead and looks to be in late-middle age. At this point in the movie she's the only live person in the castle who sees ghosts.)
Miranda: So, I was seeing this guy and he's a devil worshiper, right? Well, he's a hairdresser really, but he devil-worships on the side. And we booked this dumb tour because, you know, he likes ghosts, dead gerbils, that kind of thing... and he ran off with this Bhuddist monk! I mean, how I was supposed to know he was gay? So what about you, are you gay too?
Also, Liam Neeson repeatedly murders Daryl Hannah...which is a terrible bore for them both.