4. Not Enough Michael Sheen
Far and away the best thing about these films has always been Michael Sheen as the leader of the Volturi, Aro, who in Breaking Dawn Part 2 threatens to ruin the party by killing Renesmee, fearing her to be a terrifying abomination who needs to be eliminated. Sheen has been the warm, hammy center of these films ever since he first showed up in the second film, New Moon; he seems to be basically the only actor who gets how terrible the material is, and is absolutely having a hoot taking the piss and just enjoying himself. It reaches a fever pitch in this final film, as Sheen munches on the scenery with the might of a Centurion returning from battle, most notably as he first glimpses Renesmee ahead of the final battle and cackles to himself like a witch. But he's not in the film enough; his screen time totals maybe twenty minutes, and given he's easily the most entertaining aspect, it's a shame he wasn't used more in this or the previous films. The same goes for the series' other great actors, such as Billy Burke and Peter Facinelli.