StarKidPotter!
God I love A Very Potter Musical, it is just about the greatest thing to have happened in the HP fandom since the 7th book came out. Its got great catchy songs, a hilarous script, wonderful actors/singers and is also really heartfelt.
They also have a Sequel, both are just brilliant.
check 'em out here:
http://www.youtube.com/user/starkidpotter?blend=2&ob=4
If you have the time, watch these musicals, they are absolutly fan-freakin'-tastic!!
If you have never watched them, then you can't call yourself a Harry Potter fan.
A big thanks to the StarkidPotter Team! You guys are brilliant, I anxiously await your next project!!