I just finished S8 and was pleasantly surprised. Everyone claims the quality starts going downhill around 6 but I feel like they maintained it for the most part. Season 6 and 7 had some stinkers and a greater variety of tones/styles but also some of the best eps IMO.

Honestly, I don't think there has been a bad season yet. Season 8 was more serious/dark like early X-Files and got rid of the silliness that pervaded many season 6/7 episodes. Doggett is a great character, and they actually followed through with Scully's pregnancy storyline -- I was convinced they would get bored or frustrated with it eventually and have her lose the baby to course correct. Glad they didn't. There was also a good mix of Mulder eps -- more than I thought there would be. Also, Redrum was an absolute standout.

Maybe season 9 will finally be the one to ruin the streak. Or maybe I will be proven wrong AGAIN. Then on to the reboot...