1. Obi Wan's Distracting Fake Beard - Attack Of The Clones
I told you he'd be back.
While Obi Wan's rogue braid in The Phantom Menace was certainly distracting, his fake beard in Attack of the Clones is even worse.
In a classic case of George Lucas going with the flow and being unafraid to change his mind, much of the second Star Wars prequel (and the third) was changed after production had already wrapped. In the case of this flick, a lot of changes concerned Obi Wan, and specifically his relationship Anakin and the other members of the Jedi Council.
The issue, once again, was that Ewan McGregor had continued working after principal production had wrapped, and by the time he was called back in for reshoots had shaved off his glorious beard and cut his hair into a buzzcut for Black Hawk Down.
Consequently, there are loads of scenes in the movie where Obi Wan is sporting a wig and visibly fake scruff.
Now, what makes this worse than his previous hairpiece malfunction is George Lucas apparently thought nobody would notice, and happily cuts between the original photography and reshot footage over and over again.
What you get is this weird situation where Obi Wan can look completely different during different shots in the same scene.