I recommend "Apocalypse Now." It's a long movie and there's almost no risk of it evoking any sort of touchy-feely nostalgic feelings. Unless of course your ex was the maniacal leader of some sort of aboriginal warrior-cult. When it's over you're left with a vague kind of WTF??? feeling. Follow that with "The Deer Hunter," and you've pretty much occupied an entire evening with escapist light hearted fare.