Honestly? Who has time to rewatch a series??
For me that’s Buffy and Babylon 5, both three times. I think Queen’s Gambit may beat them, but I’m not there yet.
American Dad up to the point that Seth stopped writing for it and then I restart. It is one of my background noise shows. King of the Hill is the filler cartoon to not start the loop instantly.
Star Trek TNG and TOS for scifi
Oh and i watch Forensic Files enough that i can typically remember who did it within the intro. Similar to the original Law and Order.
I could watch nothing but Black Adder, Arrested Development and Eastbound and Down and be pretty happy about it.
I rewatch Futurama all the time. Super excited for the new season!
I like horror theme. So I’ve watched Ash vs Evil Dead, The Exorcist S01, The Haunting of Hill Twice twice so far. Out of these Ash vs Evil Dead was the best on the repeat run, so I may watch it again at a later time.
I usually end up with community playing in the background while I’m working on something else. No idea how many times I’ve rewatched it.