I'm going through Supernatural now for the first time and I'm halfway through season 7 at the moment. I actually think season 6 is a contender for my favourite. Even though it's clear they juggled several plots that they struggled to interconnect, it has several of my favourite episodes of the whole shows, less Sam and Dean conflict (which was played out by that point anyway) and the best part: more Bobby. Bobby is far and away the best character in Supernatural, so having more of him was only a good thing. Season 7 is a noticeable downgrade.

There's a lot of season 1 and 2 that feels very simple, which is to be expected when you're starting a new show and building up a mythology. It's like early episodes of Buffy or The X-Files (and probably a dozen other shows), with the monster of the week format and finding out how to kill them. Kind of like a police procedural but with monsters. When they start to delve into heaven and hell, then I think it starts to hit its stride (Kurt Fuller is great). I'm a lot less interested when it's just constant brother drama.

The problem is that I don't really care about Sam and Dean (especially Dean) but some of the side characters are great. So far, I think the episodes and seasons focused on Bobby and Castiel are some of the best ones (which is why I like season 6 so much) and it's disappointing they didn't make the most of Ellen, Jo, Ash, Rufus and more.