Some might find this sacreligious...
... but I really can't stand Rowan Atkinson. I found his role in this movie particularly loathsome, but felt similarly about his exaggerated trainee vicar character in Four Weddings and a Funeral. I'm sure that he's a very nice person in real life etc. etc., but why does he always play these over-the-top characters? One exception which I did appreciate was the successful stage comic actor he played in "The Tall Guy" for whom Jeff Goldblum's character works. It seemed to virtually be a self-parody, and while he may have been a complete bastard in his "off-stage" persona, at least we were spared the stupid voices and facial expressions.
I have to say I really enjoyed Ben Elton's book, but was disappointed by this film adaptation. In my opinion, the solitary high point was Tom Hollander, who by contrast, I have thoroughly enjoyed in every role I've seen him in, especially "Bedrooms and Hallways".