There seemed to be a small explosion of films in the '80s depicting that summer night at Lord Byron's, where Mary Shelley came up with the idea for Frankenstein. I would love to get my hands on her sister's (Claire's) journal documenting the whole event.
1986 Gothic (starring Gabriel Byrne)
1987 Rowing With the Wind (starring Hugh Grant)
1988 Haunted Summer (starring Eric Stoltz)
Ever see "Rowing With The Wind"? It's simply horrible. They didn't manage to evoke the era and it looks like it was shot on a bunch of backlots in Hollywood. (which is funny, since I think it was shot entirely on location).
And the decent level of historical accuracy is completely ruined by making Polidori a 50-something SPANISH doctor who dies of a heart attack that very summer!
I think it'll be a good year or so before I get the courage to watch Haunted Summer...
Gothic's the best, hands down...