Since these three are giving people so much trouble, here are some clues:
2 - This is somebody recounting a scene from an opera to somebody else.
I can't believe nobody recognized this one. It's part of a dialogue between the two guys you think of when you think of big fat men in the movies (other than Sydney Greenstreet or Orson Welles).
glenniebun got this one, it was Spartacus...
14 - This is from a terrifying horror film of the old school, that was the subject of a CGI-laden remake a few years back.
This little ditty was posted by somebody as a tribute to Roy Scheider, and I found it worth reposting here:
MOSTLY WORK SAFE - Mild language and some gore