It's a guilty pleasure of mine. Personally, the romance is too ham-handed for me, but the rest of it is great. My favorite scene has to be when Bill finds Eric taking a bath in his house with Old Swedish music playing and says, "I texted you three times. Why didn't you reply?"
I dislike most vampire fiction, but I play vampire roleplaying games (aw yeah V:tM oldskool) - and the lack of "BWOOOO WE'RE SO DARK AND MYSTERIOUS" in True Blood that tends to be apparent in most vampire fiction is a plus, and they aren't totally weepy and harmless either. Even Bill is a jerk and kills people sometimes.