For PT 1 the Moxxi SMGs are pretty much the only weapon you need. If you could get a Bad Touch more than once (On PC you can only get it up until like LEvel 15 or somewhere around there for main story. Don't know if you guys have that bug on 360).
Those things at LEvel 50 for what they would be used for would be beastly. Bad Touch with 70% crit damage and corrode would destroy a lot of enemies, although you still need to pack a lot of shock weapons in TVHM. --- Because F*** You is why