Yeah Hell's Kitchen started in the UK but Gordon was trying to teach relatively minor celebrities how to cook in that one rather than members of the public. He only did the one season and other master chefs have taken over since.
The most recent one only finished a couple of days ago and had Marco Pierre White as the head chef. He used to employ Gordon and one evening after a particuarly fraught service he, unbelievably, managed to reduce Gordon to tears
In the show Pierre White rarely if ever lost his temper but he was certainly quite an intimdating presence.
Anyway the 3 seasons of Hell's Kitchen USA are all great fun, really compelling to watch, I think Gordons even more explosive in this series than he was in the UK version and he was pretty volatile in that one. His assortment of one-liners and put-downs are hilarious, he's definitely the pivot point around which everything else revolves. You can see how much his trainee chefs want to please him and how much his praise means to them. His promise to Julia the waffle house cook that he would pay for her to go to culinary school was very moving. You can tell how much he really cares deep down.
Oh and Kitchen Nightmares is great too, and I think although certain things are embellished, (for watchability reasons if nothing else) I think that executive chef would be surprised at just how bad the hygiene levels are at certain places. I have a feeling it's much closer to reality than anyone would like to think.