I've never walked out of the cinema but I did start to nod off watching Get Shorty it was just boring as fuck. I don't go the cinema much these days, I can only remember watching 2 this year.
Dungeons and Dragons: Honor Amongst Thieves (excellent movie) and Mission Impossible whatever the current number is (watchable but nowhere near as good ad D&D)
I've started and failed or nodded off to loads of films (and shows) at home. Eternals has the dubious distinction of being the only Marvel film to put me to sleep. Mrs Q is terrible for nodding off, I used to wake her up but these days so long as she isn't snoring I leave her be. She always seem to wake up and say "What happened?" just as it finishes.
I side with Orang Utan on this though Every Which Way But Loose and Every Which Way You Can are great films, Clyde steals every scene he is in and the scene where the cops pull up the gormless biker gang whilst they are wearing coloured wigs is hysterical.