I find him incredibly arrogant, that puts me off.
I've never met him personally, but from seeing him on telly, I think he used to be arrogant but has now become much less so, although he's obviously passionate about his quizzing skills and maintains the persona as his character on The Chase.
I remember seeing him on TV about 15 years ago in The People's Quiz, where he came second in the grand final to an outstanding 16yo girl, and he was very arrogant then - and quite bitter to lose to a child; but he seems very much more gracious (if still openly disappointed and frustrated when he loses) now.
I think I read that he has ASD, as does Anne, which might go some way to explaining his apparent arrogance. Chris Packham does as well, and his manner could often be interpreted as blunt and arrogant; but he isn't at all - he's just passionate and fascinated about his areas of interest and keen to share his in-depth knowledge.
Shaun is my favourite of the first five (Darragh seems very nice, but I haven't really seen much of him yet to be able to judge). A friend of mine was on there once, and got him, and she confirmed as much. Apparently, he's the only one who goes to meet the contestants in the bar afterwards, whether he wins or loses. He's obviously happy to play along with the 'Mr Boring' persona they've assigned to him, but you can see that the required 'trash-talking' doesn't come naturally to him, even just as part of the act. Paul is very similar in that respect.
I wonder if it has anything to do with their backgrounds and the fact that, for the other three, quizzing IS what they do and so they have more of a reputation for brilliance at it to uphold. If you're a qualified doctor and popular comedian or a high-ranking barrister, I imagine you feel like you have less to prove if you have another highly-respected string to your bow.
If they do seek another Chaser - and aren't specifically after a female one to even up the numbers a bit more - I really, really want them to get Shaun Williamson. He's another one with amazing general knowledge, a talented actor and great singer, and yet so humble and, by all accounts, a genuinely lovely bloke. It might get a bit confusing having two Shaun Ws on the show, but they could always give him 'Barry' as his rather underwhelming Chaser name and make him change it by deed poll 