Even though I listed this movie over in the "what movies you never make it to the end of" thread because every time I see it, I fall asleep somewhere between when the monkey bangs the bones together and when HAL locks the guy outside the ship, completely unconscious until I suddenly wake up in the middle of the "what the heck is all this crap flying around the screen" sequence and watch the rest of it in a stupor trying to figure out what is the meaning of the guy watching himself get old in the bedroom ... even with that track record, I am DVRing this and will watch it again because I've never seen it in HD.
HD makes everything seem new.
EDIT: I've not watched the whole thing yet but WOW, what a difference. This is doubly amazing because there were no CGI effects back in 1968.