As a note, I think the dub is as good if not superior to the sub in the case of Black Lagoon. I know that's practically heresy, but it works really really well in a series where they're actually supposed to be speaking English but also involves Russian, Chinese/Taiwanese, Japanese, Irish, and American characters. The only thing you miss out on is Revy's Japanese voice actress speaking the most egregious Engrish you've ever heard.
Also, hope you don't have much against language because this show is...well...not exactly light on the language or violence.