I'm going to do you all a favour now and recommend one of the best fan made artistic endeavours to hit the Potterverse since Potter Puppet Pals ... A Very Potter Musical!
For those of you not familiar with AVPM, it's a fan made musical that was performed by a theatre group in Michigan purely for the love of Harry Potter. They wrote it, came up with the songs, got the costumes together and put the whole thing on as a labour of love. And we're not talking about some dinky little five minute parody here, this is a full length musical that goes for a couple of hours!
These guys are legitimate fans, they definitely know their stuff. There's plenty of in jokes and references back to the books, and quite a few insights that'll have you laughing. But really, you're going to love it for the music.
The performances are hilarious, especially the girl who plays Draco Malfoy and the guy who plays Dumbledore. Harry, Ron and Hermione have a great rapport and play off each other really well, and the ridiculously tall fellow who plays Goyle just steals every scene he's in.
The videos are broken up into two groups, act one and act two, and then into parts. If you want to see them on a playlist which will take you from one to the next without you having to worry about finding the next bit, you can go here.
Seriously though, if you're a fan of Harry Potter and you haven't seen this then you absolutely must watch it! Find a couple of hours, sit yourself down, and just watch it through. Once you have, the title of this entry will totally make sense.
You can thank me later.