I think there are 5 good seasons of SMALLVILLE on the writing side. 1-3 are decent, 4 meh, 5 & 6 felt like it was getting back and 7 suffered from the writers strike. I have a hard time defending 8-10.![]()
I watched all 10 seasons, and honestly for me Seasons 8-10 were the best. He was long out of High School, Lana was mostly gone, superhero things started happening (even if the no flying/costume for Clark thing was moronic), it had a good supporting cast, and it had the best episodes of the series (the Legion of Superheroes episode and the JSA story are my personal favorites). Even then it had problems (the finale was horrible, and the whole Doomsday arc sucked), but I'd say that if I were going to rewatch Smallville, those would be the seasons I'd be most interested in rewatching.