Not a great year for great new TV. There are some decent shows out there (Prime Suspect, Person of Interest), but it doesn't compare too well to past seasons. However, one new show is good--Grimm. Imagine Buffy (or maybe Angel--no high school cheerleaders here) combined with a good cop show. Now imagine that it somehow doesn't cater to the Twilight crowd. At all. If you're looking for romance with your werewolves, you won't find it with Grimm. The protagonist lives with his long-term girlfriend (who we don't see much of), works as a homicide detective, and--well, the supernatural elements are important, but I don't want to introduce any spoilers.
As far as violence, sex, darkness, etc. goes, I'd put it on the same level as X-Files. Some violence, a little dark, some good scares. And all four episodes (so far) are available on Hulu (although the pilot may not be there for much longer). Highly recommended.