I see quite a few people saying Puella MAgi, but that doesn't really count because you're suppose to watch through it twice at least to grasp the entirety of the anime?
I'm seen it 5 times at least, (including Rebellion) I was going to make it 6 watching the dub but ewwwww...
Also I'm rewatching Clannad because the feels. I can see myself rewatching this one every few years just because it's that good imao
Also I rewatched Sonic X because I watched it dubbed first when I first found anime.
...Actually I have rewatched almost every anime I've ever seen because I watch it by myself and then with my siblings. (it's fun to see their reactions.)