It seems like if you like the show, for the most part you find it to be re-watchable. I think a better question is what shows are there that you enjoyed the first time around that are not re-watchable. I can think of Lost. I'm not sure what else.
I've watched Deadwood three times and it has gotten better each time.
The OC is definitely re-watchable
I've watched Deadwood three times and it has gotten better each time.