The Jonathan Ross Show: UTV, 9.30pm X Factor judges Gary Barlow and Tulisa Contostavlos (below) discuss the latest series as it reaches the judges' houses stage.
The host also talks to actor Ewan McGregor about his new film Perfect Sense and comedian Steve Coogan appears in the guise of his alter ego, Alan Partridge. Cee Lo Green performs his latest single Cry Baby
CRISIS IN CAMELOT
BBC1, 7.50pm The new series starts tonight and Merlin must confront Morgana's dastardly schemes which threaten the very future of the world.
Hellish creatures are about to be unleashed across Camelot and Arthur believes he can only save his kingdom by sacrificing himself.
PLAY IT AGAIN
Westlife: For One Night Only
RTE 1, 11pm Music purists may scoff at some of their more naff material -- but the boyband some people love to hate has sold a phenomenal 44 million records.
They are also the only group in British or Irish music history to have their first seven singles hit the number one spot.
Gay Byrne interviews the guys.
BBC1, 9.25pm The Emergency Department staff are sharply divided on how to treat some chronic heroin addicts.
The nightmare world of two recovering junkies provoke the more indulgent Charlie and Linda to take on matter-of-fact Jordan and Lenny.