Well... Not re-watch a series.. Moreso re-read the books.
I was cleaning out my basement and saw a crate of books. I looked all of them over and put them in order, and I noticed an empty space. Hell, I don't know how I was able to handle the fact that I was missing book 54, the final in the series of the Animorphs, the first time I read through. I went out and bought it, was about to read it, then felt bad. I decided I had to re-read them all before I read that one. Got to book 54, and realized that I enjoyed them more the second time through than the first time.