Citizen Kane
Maltese Falcon
Sound of Music
Fiddler on the Roof
Saturday Night Fever
Grease
Little Shop of Horrors
Rocky Horror Picture Show
Finding Nemo or any other animated movie. I did see Shrek finally, this past year.

Any musical, popular or otherwise (I considered these the land mines of the movie industry as some are sneaky about it then boom, musical).

... and any of the new Star Wars movies

There's too many to name, estimate 90% of those listed by others, are on my 'no see' list.

A few years back I read a 100-list of titles and IIRC had seen maybe almost 20.

My enjoyment of 'going TO' movies took a serious nose dive about 30 years ago. Can't account for maybe 1 in the last 5 years.

Deep Throat, the reviews were always terrible.