People think the Volturi are bad because they think the Volturi doesn't give the Cullens a break. Actually, the Volturi are just doing their jobs. They wouldn't be after the Cullens all the time if the Cullens just stopped breaking the rules all the dang time. Gosh, it's like they can't learn from their experiences.
They're vampires, but they are very, VERY humanized. There is barely anything vampy about them. The main reason why people like them is because they can relate to them. They should have just been humans if they weren't going to act like vampires.
Who needs the Cullens when you have the Denalis, the Romanians, and the Volturi? Carmen is as good as Esme; Aro is as good as Carlisle (well, sorta); Kate is way better than Alice; Felix is as awesome as Emmett; Irina is sort of like Rosalie; I'd rather deal with Stefan than Jasper; etc.