Well, it gets my vote, standing right in front of a Limonaire organ which is belting out the Radetzky March at top speed is one of those things that has always made goose bumps appear all over my arms.
EDIT- I looked on YouTube and there's plenty of great fairground organ footage there, I'm still looking for the Radetzky March but meantime, for anyone interested, I found this footage of two children younger than Charlie and Sam knocking out a fantastic version of it on a piano...
http://www.youtube.com/watch?v=HW-S3jGnAqQ
This Strauss waltz is the one piece which most comes to mind for me when thinking about mechanical fairground music.
I've always wanted to restore a fairground organ, I'll have to have a look on eBay next time I've had too much to drink!