For me, it's three-fold: 1) I just like recognizing familiar voice actors like Vic Mignona and Christopher Sabat, 2) Some things are conveyed more directly in one's native tongue (can't think of examples, but I swear it happens xP), and 3) I do prefer not to need to give the screen (in particular, the text on the screen) my complete undivided attention. That said, I also acknowledge that the emotion of the original Japanese voice actors usually isn't matched in the dub. For whatever reason, they're much more consistently able to convey the extremes.