Only ones I watched all the way through was 1, 3, 4, 5, most of 6, most of ones with Mir as coach and all of season 10.
Luckily with tuf, I can tell by first or second episode if I would get invested or not.
Still watch all but I remember less and less.
I think it was 10, heavyweights with Mitrione, Roy and kimbo when I stopped watching. I started watching from the first season.
All. Mostly just watch the fights the last several seasons.
Liddell/ortiz and franklin
I stopped watching tuf at all during the chuck/tito season.
the HW season was the last good one IMO