I don't care for all of the FN chefs - there are a lot of shows I don't watch. Of those I do, my thoughts are as follows.
Rachel Ray - Great, quick and easy meals. On occasion I thinks she talks too much. I know that what makes her more personable but sometimes she crosses the line.
Paula Dean - I love her style of cooking, but I can't stand her voice.
Emeril - I like how he plays to the audience on Live, but he also plays to the camera too much. It sometimes seems like he is trying to fill dead air, which to me is noticeable big time. I like his cooking, though.
Alton Brown - The guy is a genius, but frankly I don't want to know that much detail of everything I eat. I think he's better as emcee of ICA then cook/educator on Good Eats.
Tyler Florence - I'm with whoever said here he talks too fast. He needs to try decaf or something. And what's with saying "fantastic" five hundred times per episode, regardless of the show?
Giada De Laurentis - Talk about easy on the eyes! I love her show, and my being Italian I love what she cooks. She has a great style all her own of how she teaches on the show. She breaks it down very simply, but not so much as to insult one's intelligence.
Anne Burell - I haven't seen her show, but based on previews I think I'd like it. I loved her when she was sous to Mario Batali.
Guy Fieti (sp?) - He's sometimes too over the top for me, but I like him, his style, and his food. I'm not "down" with the phrases like "Off the hook" "hooked up" etc. Guess I'm old fashioned.
Bobby Flay - My hero. Love him on everything he's been on, both style and flavors. I try to watch his sauces closely because they are so simple but pack a whallop!
Morimoto - I am mezmerized when he gets down and dirty with his knife skills. I can see why he is considered a master chef.
Mario Batali - seems to becoming more commercial, which I don't care for. The man is a wealth of knowledge of all things Italian, but can also talk much too fast to understand.
Kat Cora - Most probably know she is Executive Chef of . . . . . crap, I can't recall which magazine. She's fun to watch, but as others have noted, she's not often challenged. Though tonight Opera's former chef is challenging her in ICA.
Michael Symon - I personally think John Besh should have won, but it wasn't my call to make. Michael is too "bad boy" or "radical" for me, which lends itself to my old fashionedness again, I suppose.
Robert Irvine - while I realize there were discrepancies about his resume, the man is brilliant when it comes to cooking, and in particular doing so for a crowd. I liked Dinner: Impossible better with him over Michael Symon.
I've learned tips and tidbits from them all, and probably could if I watched some of the other shows as well. Over all I'm not a big fan of the ladies that are on during the day, of course aside from Giada and Rachel. I'm somewhat interested in the Chef Jeff project. I saw him on Dinner: Impossible with Irvine; Chef Jeff didn't seem to quite follow the time crunch which seemed to hold Robert up. Chef Jeff was more wrapped up in teaching the kids, which is all fine and good and is his style, but Robert was having difficulty because he was overall responsible to make sure the mission was complete.
One of my old school favorites to watch was Martin Yan with his show Yan Can Cook.
I also dig how Emeril will often give props to Julia Child during his show. I didn't really care for her shows or style, but she certainly was a pioneer in such shows. A heck of a cook too!