Charming monster? Same here, Winx!
Anyway, I vote for Bowser. Like Winx said, there's a charm to him that gets my vote. I don't know why, maybe it's because he's persistent on defeating Mario though he never wins.
Or maybe it's because it's just something about his look that makes him look cute. I guess that's where the charm comes from. And I keep thinking that somewhere deep down, Bowser might have a good side to him (aka ''Super Mario RPG syndrome'').
Straight to the point, Bowser would win in a fight against Tatanga. Well, then again, it would be the ONLY thing he ever won (excluding any matches in Mario Golf where Mario is too lazy to show up).