The first season has a lot more of the episodic, almost cheesy filler episodes. Once you get into some of the later seasons and the plot starts getting filled out, there'll be a lot less of the "hm, they're just going through their old books of monsters" feeling. In fact, filler episodes will start to feel like sweet relief ;-D

I thought the Benders was one of the most powerful episodes of the first season, exactly because it was about the weird shit humans can get up to.. and it really throws Dean's cynicism into relief.

(It was also the impetus for my vewy first wincest fic, but that's neither here nor there.)