Since the list appears to only contain some of the current biggest name celeb cooks, I voted for Gordon. A lot of people think he is a huge jerk, but compare his UK shows to his US shows and you'll see a lot of that attitude is probably due to Fox pushing for it to get ratings.
If other would have been an option, I'd have chosen it to vote for Julia Child or Rick Bayless if I had to vote for someone still with us. He may not be as big of a name to some, but his PBS show is really good and he also won season 1 of Top Chef Masters. A lot of names in the comments would fit in a larger list of my favorites also, like Justin Wilson, Alton Brown, Martin Yan, etc.
Those of you claiming some of the names don't belong on the list, should reread the wording. It says cook not chef, so names like Rachel Ray do fit. Some of the names Woot added to the poll have explained that you can't call yourself a chef if you haven't managed a kitchen, but cook is a perfectly acceptable title for some of the listed celebs. I personally can't stand Rachel Ray anymore, but at least she doesn't claim to be a chef or lie about her background like Robert Irvine did.
Regarding Alton Brown, he is a graduate of New England Culinary Institute, so has professional training and would be a fine choice. Padma started out as a model, but has hosted cooking shows before Top Chef and has 2 cookbooks, even though I'm unaware of any formal training.