I'd have to say that Splash Mountain has the best music and it's just so happy sounding! It definately gets stuck in your head, but not in that annoying Small World sort of way! I think an important part of it is that not just the music has to be good, but the ride that goes along with it does as well. While Small World is a WDW classic and I go on it ONE time during each visit, it is without a doubt lacking. Splash Mountain on the other hand I could ride again and again, the ride and the music that goes with it just works! But just because I chose Splash Mountain does not mean that I don't love just about every ride's music, they all go so well with their rides, that what helps to make Disney what it is, all the attention to detail and the exceptional time they put into making quality rides, attractions, parades, restaurants, etc. It is truly an amazing place!!!!