Barry is my fav, because he is funny and I don't find him annoying. Being quite a silent and introverted person irl, I had many friends like Barry lol, so it kind of resonates with an actual friend I would have, I guess. I like his design, love his battle theme and honestly, a little bit like Nemona, the fact that he's always so frenetic and energetic, justifies him wanting to battle so frequently with us. Also has a nice story going on, with the lost pride when he's defeated by Jupiter and taking revenge by helping us at the Spear Pillar and then trying to beat his dad.
On the other hand, I found Hau very annoying.