Which airline is best for Economy Class, choosing from United Airlines, Air Canada, or Continental Airlines?

By best, I mean which has the most comfortable seating and it would be nice to know if it had any of these airlines had the small TV's in the backs of the seats. This is only a 1 hour and 30 minute flight I'm inquiring about, so there is no object of sleep or any prolonged discomfort. Please remember I will be flying Economy/Coach. Thank you for any and all answers in advance!