Most responsible one would be Ra'si, easy~ But as for the least responsible... Likely the Argonian Noble from Auridon named Bites-too-Much!
Bites would likely be glutting her face and making a mess of some well-stacked dinner table as food crumbs go flying about; all while Ra'si just tries to be on stand-by once the Argonian inevitably ends up riddled with the mother of all belly aches!~