10. Season 7
With Smallville leaving its High School and college days in the past, it allowed the show to tackle more comic book-related storylines. We saw that in season 6 with the formation of the Justice League, and it’s a trend that continued into season 7. This was clear from the offset with the arrivals of Bizarro and Kara Zor-El, a.k.a. Supergirl.
Tom Welling was great in the dual role, and Laura Vandervoort quickly became a welcome addition on the show as the Girl of Steel, but something about season 7 didn’t quite work. It started off very well, adopting a more mature and haunting tone as the characters dealt with the fallout of the season 6 finale but the longer it went on, the messier it got.
Lex’s dark days spiral had outstayed its welcome at this point, so it’s not surprising that this was Michael Rosenbaum’s final season as a regular. He was excellent as always, but the show had taken pre-Superman Lex as far as it could go, so it was time to move on.
Season 7 wasn’t the most offensive season of Smallville, but it’s the hardest one to remember fondly because it’s really quite dull. The show needed a reset and thankfully season 8 was able to do that.