Lip Sync time, at least for the first two. The third is actually the video behind that art in the drawfriend the other day. Apparently it was all drawn specifically for it. I actually watched Code Geass a while back, I'm surprised I didn't notice the similarity in the images.
Regardless of your opinion on anime, that artist is awesome.
1.) MLP:FiM [PMV] What If - Eric Whitacre - Paradise Lost
2.) Pinkie Sparrow
3.) Code Luna - Friendship Is Geass (Also have a comparison)