Having never been in a band that has existed outside of the confines of a basement or lasted for more than one week, I've never played live music on stage. But I've decided that if I did I think Man The Ramparts by Botch would pretty much be the most fun song to play in front of people. Even better if you get to sing it. Screaming WE ARE THE ROOOOOMAAAAANS in people's faces would be awesome. Then you get to do some choral chamber music creepiness, then the last few seconds are unbelievably loud and heavy. Plus you could finish with this glorious mess if you so chose.
https://www.youtube.com/watch?v=_UYRsT9QVxc

You?