Same here. If you'd asked me during seasons 3 and 4, I would have been sure that I'd rewatch it at least once or twice. Having seen that final season, there's no way I'll ever watch it again. Bit like Lost, in that respect.
It's a strange one for sure.
I think I've re-watched the every season apart from the last multiple times.
Since the final season, I've not re-watched a single episode and even being stuck indoors and this being on Sky, I've got no interest.
I even re-watched a few episodes of Buffy the Vampire slayer last night and I've seen those a million times!