4th Horseman is the most powerful close range burst DPS in the game. UR is a decent enough shotgun. SGA is useful in VoG, and not much else. NLB is ok for pvp, and not much else. Worst exotic? Thanks to the AR nerf, I'd vote Hardlight. Unlike the Nechro, it has no element. Unlike Monte, it doesn't enhance specific play styles. Unlike Suros, it can't heal you. All it does it lots of poor damage. It is only good in small areas, and only against weak enemies. It's the only exotic that has absolutely no saving grace.