Monte Carlo is good, but nothing special unless you specifically build around its exotic effect and maximize its payout for you. Excellent for a Defender Titan or either flavor of Warlock with armor that gives bonus super or grenade energy for melee kills; in the case of the latter, a Voidwalker with Embrace the Void will have both abilities ready to use quite often. Hawkmoon is one of the best, I honestly forgot to mention it. In PvE luck is hardly a factor, because against anything worth that bonus damage, you're dumping the whole magazine in anyway, so it's just bonus DPS. In PvP, a lucky enough man will kill you in two hits, and a skilled but unlucky man can still beat you with three. If hand cannons are your speed, Hawkmoon is hard to beat, but the Regime and Mythoclast will always be considered more reliable, more forgiving, or easier to use.