Most anything with John Wayne. Wife doesn't much like such movies, but she'll watch them. My arm is usually numb from her falling asleep on it before the movie is halfway over.
We mutually fell asleep watching 'Citizen Kane'--in the middle of the day. To date it is the ONLY movie I have ever fallen asleep from watching due to sheer boredom; it's probably the most over-rated film ever. I feel it's only considered "good" because of the hard-on most critics seem to have for Welles.
I feel I'm fortunate in that my wifey will not only watch, but LIKE, movies like 'Evil Dead' and 'Mad Max'. I've also been trying to introduce her to various '80's movies which she has somehow never seen.
J_A_B