Over-the-top villains like Khan are nice to have, but are not necessary for every film unless you insist on conforming the franchise to the superhero comic-book mold. V'Ger was technically the adversary in TMP, but V'Ger didn't rug-chew the way a traditional hate-driven villain does. It created plenty of death and destruction as a byproduct of its cosmic identity crisis. The trick was to setup events in such a way that the Enterprise crew tries to _understand_ the adversary and not merely conquer it via phasers and fisticuffs. It's unfortunate that How to Train your Dragon 2 is not doing as well as the studio hoped, but that's the whole premise of that universe, that Hiccup represents engagement and peacemaking. I think there's a direct connection between how Hiccup tries to resolve conflict and how Trek (TNG especially) tried to resolve conflict. The problem is, culturally, we'd rather have a thrill-ride with cardboard cutout villains that can be knocked down like a videogame than to really think.