I once worked with Rufus Hound shortly after he’d appeared in a play (I want to say One Man, Two Guvnors) with Robert Lindsay. Safe to say there was no love lost between the stars - Rufus had nothing positive to say about his cast mate.
At a similar sort of time, I did some work with Ross Noble who was a complete delight. Other celebs I’ve had pleasure (or otherwise) of working with are James McAvoy (lovely) and Nell McAndrew (agent hung up on me - this was in 2017, not 1996 when she might have at least been a name!)