I work at a UK based film studio (in the offices). I meet a lot of celebs and most are quite different to how they appear on tv. I’ve met quite a few of those mentioned in this thread in real life.
James Cordon - awful to those he perceives as ‘beneath him’. Sucks up to other celebs but can be rude and a diva with staff. Not a nice person.
Beyoncé and Jay-Z. - both very lovely and polite. Kept to themselves and weren’t overly chatty, but definitely weren’t rude when approached.
Ainsley Harriott - lovely, lovely guy and a lot quieter and more softly spoken in real life than he appears on tv.
Nicholas Lyndhurst - very nice and down to earth. Ate lunch in the work cafe every day rather than the posh fancy one. Greeted everyone.
Holly Willoughby - awful. Had to liaise with her pa several times during a shoot. She was rude on several occasions and very much up her own arse!
Phillip Schofield - he really irritates me on tv but was actually lovely the few times I met him. Very polite and pretty much just got on with the job, no fuss.
Daniel Craig - polite but quiet and reserved. On set he does his scenes and keeps himself to himself. Never rude to anyone though.
Ann Robinson - despite her character on The Weakest Link, she was always lovely with our office staff. She used to regularly stop by between filming and have a chat. Very nice lady.
To be honest, the A-list celebs tend to be the nicer ones. The worst are usually the reality tv ones. Very arrogant and seem to think they can get away with treating people like shit. We had to do a shoot with the TOWIE lot a few years back and, apart from one of two, they were awful. Had huge lists of demands.