Here are some I just found. It was suggested that I bring them to this thread.
I really like this one about Cas/Dean:
YouTube - Kryptonite (Dean/Castiel)
An enterprising Misha fan has put together a video with a lot (if not all) of Misha's sexy scenes from his various TV shows/movies, plus some where he is simply looking scrumptious. It's definitely in keeping with the "hottie with a body" theme. Warning: you might need some cold water or a fan.
It can be found here:
YouTube - Misha Collins #1 Crush
For some kinder, gentler scenes, these are from "Finding Home." I love the one where the dog eats out of Misha's plate.
YouTube - Tribute to Misha Collins - Finding Home