Like a lot of fans of the show, I thought that the last show of Season 5 would have made for a perfect ending to the series. It's one of the best TV episodes of all time for me. So I was deeply skeptical of Season 6, which started off slowly but built on a solid return to the show's small-time monster hunting, with the brothers chasing individual monsters in each show rather than pursuing some grand scheme. But over time, the Winchesters were once more dragged into the larger picture as Castiel goes rogue and tries to become the new God. Fortunately or not, that doesn't pan out and a new breed of creatures, Leviathans, are released onto Earth to start Season 7.
That's where Season 7's larger plot kicks in, as the boys continue with smallish hunts that start building to a worrying picture. It seems that the Leviathans are not very nice- to anyone. Humans are food, demons are filth, and angels are annoying barriers. None can peacefully co-exist with the Leviathans, or at least, that's how it appears. So the boys have to go and take care of them, particularly their leader Dick Roman. They do get some help from reliable Bobby, although Bobby's role with the boys takes a very significant left turn in the show (I quite liked the episode where it first forces that turn). Cas also returns, and as with Bobby, he also has a very new relationship with the Winchesters. This helps keep the show fresh, although Dean's angst in spots is a little old. Meg shows up too, although she is fairly standard Meg- a helpful, but ultimately can't be trusted demon. A great "new" character is Frank, the paranoid electronics and surveillance wizard who helps the boys track down Dick Roman. So the solid cast of characters for season 7 are an interesting mix of familiar and different.
Overall, this season is a mix in general as we get big-picture hunts (against Dick Roman and his kind) as well as smaller hunts that are also tied to the big picture. These smaller hunts help bring the show back to its roots, where I think it performs best. The acting is very good in the episodes and the stories are interesting and well-developed. The mega-plot is interesting, as the leviathans are very different from the demons and angels of past seasons. I'd like to give this season 4.5 stars. I'd have no real problem with someone calling it 5 stars other than I think it's not the best (or as good as the best) of all the seasons, so I didn't want to give it top marks. Don't take that as a sign that this isn't a very good season. It is. It's not the best season to start with if you are new to the series as there's a lot of character development that builds on past series, but for seasoned fans of the show, this is definitely a solid season to add to any collection. So if you like exciting, suspenseful, and cool monster hunters (the show still uses great music), then Supernatural is for you, and Season 7 is certainly one of its stronger seasons.