Smallville sure as hell isnt GAINING new viewers in its NINTH season, so I can only assume these weekly ratings spikes are due to fans finally following it to the new night. Either way, nice job.
RE: S4, S6 and S7
Looking at the Wiki entries for the episode lists, I just realized that S4 has only 2 episodes I love (Crusade, Transference), while S6 has only 1 (Zod), and S7 has none :lol
To finish it off, S1 has 5 (Pilot, Rogue, Leech, Nicodemus, Stray, Tempest), S2 has 6 (Heat, Red, Insurgence, Rush, Rosetta, Exodus), S3 has 7 (Exile, Phoenix, Perry, Shattered, Asylum, Memoria, Covenant), S5 has 5 (Arrival, Hidden, Splinter, Solitude, Reckoning), S8 has 2 (Bride, Doomday), and S9 has 2 (Echo, Kandor).
Exile is my favorite episode of the show. I loved the whole Metropolis/Red-K Clark arc. Too bad they wrapped it up so soon.
EDIT: I dont generally jive with fan music videos, but I saw this one a few years back, and it appears he updated it recently so that it covers S1-S8/ Very well done, and the music is fitting.
http://www.youtube.com/watch?v=NzYFSsFD2qk