What bugs me the most is how small people's movements are. A good chunk of skits I see consist of walk across the stage and making weak arm gestures for 2 and half minutes. People past the first row are not going to be able to see what's going on, and most of the audience will most likely be falling asleep. Good ideas are easily ruined by this and I want to scream. It doesn't take much. Just making your movements bigger, no matter how stupid you feel, because you look more stupid just standing there. A popular Disney song playing won't make the skit better.
Maybe I just take it too hard because I'm a professional performer.
Newcon 2013 (Portland OR):
Sylveon - Pokemon: 50%
Akihito Kanbara (Idol) - Kyoukai no Kanata: 5%
Eren Jaeger - Attack on Titan: 10%
Sakuracon 2014 (Seattle WA):
The Hooded Man - Final Fantasy 4: The After Years: 0%
Yuuka Kazami - Touhou Project: 0%
Witch Elly - Puella Magi Madoka Magica: 0