The kinds of things I do feel like rewatching are those movies (and sometimes TV episodes) where there is a lot of subtle or complex stuff going on. Like hints to something that only get revealed much later that I'd want to go back and see with hindsight. You know, things where having more knowledge helps you enjoy them more. I wish I had a good example to give.
But really there are so many things to watch I don't usually have time to see something I've already seen. I'm also always worried that something won't be as good the second time I watch it, no matter how ingrained in my heart it is.