A few not-so-nice ones I've come into contact with via work:
Aled Jones is just horrid, a rude, full of himself, arrogant pig. He's like butter wouldn't melt in his mouth when the camera is turned on though.
Former Magpie/ CITV/ Talk Radio presenter Tommy Boyd is a two-faced bully who wasn't particularly well liked by many of his colleagues, particularly when he returned to talkSPORT the second time around. A lot of people who've worked with him don't like him at all. I've experienced his rudeness first hand.
Sky cricket presenter Charles Colville is also a nasty piece of work. He's the only member of the Sky cricket team I don't like as a person, and I include the sometimes-prickly Sir Ian Botham in that.