Rachael Ray jumped the shark when she tried the talk show format. She's just not the type for that! Methinks she copied Nigella's foray into the format. Nigella kind of pulled it off; Rachael Ray can't.
I take it Rick Stein hasn't invaded Yankland like he has Oz? The Lifestyle/Food Channels must have bought a job lot of his shows: they're always showing the bugger! Now that that $%#^ing dog Chalky is dead, and Stein's wife finally divorced him, perhaps the show output will slow down.
I like Alton Brown's shows and the all too short series by Heston Blumenthal, Kitchen Chemistry. Ever Wondered Food is good, as well.
Anything Tyler Florence does seems to be good, and Michael Chiarello is borderline watchable.
Apart from Cook Like A Chef, Canadians can't seem to make cooking shows.