Definitely Color Your World for me. I'm surprised it actually is #1 here as I rarely hear people mentioning this song.
It simply has everything. The beginning immediately caught my attention and I still find myself singing those lines in the kitchen pretty often. The most outstanding thing for me though is how well it manages to shift between different kinds of moods. Starting off pretty melodic with a little desperate ring to it, building up to the brutal "The horror!" part and then slowly falling apart until the arpeggio stuff starts. I think the interlude that leads to the arpeggio part is the best musical moment I've ever heard in my life. It just sounds so wonderful how all the different melodies overlay. The "far far far away" singing, the guitar solo, the rhythm guitar, the other background voices...there's just so much at that moment and it sounds absolutely breathtaking.
But as many people mentioned, there's really many tracks that can easily get a vote here for me as well. N9, for example, has almost no votes, yet I still think this song is something special.
