Some of my favorites are Mario Batali, Bobby Flay and Alton Brown. I really like a chef that explains why different foods and ingedients do what. Also Mario gives great history lessons with his show. Another of my favorites is Mark Bittner, although he is not a chef by his own admission. I like to watch him go head to head with a pro and create a simple "home" version of a complex restaurant dish.
About some of the others mentioned...
Emeril - I do believe he has a gig that pays the bills now, and is just working the gig. I do like to watch him make things, but he gets laughs simply because he is Emeril, not because he is all that funny. Last night I saw him dump orange liquer into chocolate. I though that was a no-no, but I could be wrong.
Rachel Ray - (Like Bittner, also not a chef, by her own admission) I like her simple approach to cooking. The home cook does not have a staff and possibly not the skill with which to prep and prepare a restaurant quality meal. I have to agree with some that her "gig" does get old. I like her $40 a day show just to see the different restaurants and locations. But she IS a lousy tipper. $1.50 for a $10 meal? I tip more than that at a buffet!