I would love a highfive emote like in Team Fortress where you throw it up and it only completes if you some activate it on you. The cold shoulder when no one interacts with it always makes me laugh. I would also like a ballroom dance emote that works the same way but that would be a bit harder with the size difference with characters.
For odd emote I think a Soul Eater like Excalibur face would be awesome.
