There's been some very well-made fan trailers out there that would make awesome movies. My favorites:

Green Lantern:


Thundercats:


Legend of Zelda:


Care to share any fan-made trailers you have stumbled across?

Out of those three trailers, the Green Lantern one was the only one I hadn't seen. I must say I was mighty impressed with it. Looked like a genuine article at times. The ending of the trailer was kinda poorly done though, compared with the rest of it. For example the sound quality of the Green Lantern oath was rather poor.

I saw the Zelda trailer when it first came out and I thought it was the funniest thing ever. It's technically not a fan trailer though since IGN funded it as an April fools joke.