sigma's are crap
glock's have stupid grip angles
1911's were given to us from God through the profit John Moses Browning
XD's rock, and whoever can't figure out how to field strip it needs to give up at life. As for what round is best, go with what you shoot best. If you shoot best with a .45, then that's what you need. If you shoot best with a 9mm, then that's what you need. Beyond that, any round is going to make someone second guess their actions.