I've seen both.
They made us watch both in school.
Schindler's list was hella boring. It's like slavery movie for Jews. More emotional than anything.
Cuckoo's nest was goat. Jack Nicholson basically being a sane person in a insane asylum. But he's so fucked up, it's like he really belongs there. There's so much to break down in that movie too.
Easy vote for me. Cuckoo's