Don't do that to yourself. Season 5 is the original show runner's intended ending. It goes for 15 seasons and a lot of it's flawed charm comes later. Like Futurama, everyone has their decided ending for supernatural. Mine is after season 11.

It's a personal take, but I think that when it stops taking itself as seriously it becomes more fun to watch.

6 tries to resemble 5 alittle, and 8 are quite decent, and only 11. almost every other one is wierd and awkward.