First of all, the main differences:
The cleanliness of their kitchens. I know they are probably steamed cleaned to within an inch of their lives before filming starts but at the same time, the odd bit of 'normality' would be nice. What family with young children has gloss cupboards? We all know that one touch, and they need a clean! They do not stay clean and tidy for long.
Before they start, everything is laid out, all ready weighed/chopped etc. Maybe it is just me but I don't have this done before I start.
Their clothes are spotless from start to finish. I don't know about you, but I at least look a little dishevelled like I have been cooking whether it be a little flushed or covered in a light coating of flour, whatever it is, I know I have been cooking!
I have seen some differences between American and British cooking programmes. The Brits have a lovely full fridge more often than not. Whereas, our American counterparts seem to only have what they need for that recipe. When I am watching a programme, even though I know they do not live on set, it would be nice to build an illusion that they live there. Or does that mean there is less money in the UK and they do actually use their own homes?!
Talking of fridges, they are always clean; sparkling clean! I do like a clean fridge so I don't mind this one too much, it just reminds me to go clean mine.
The American programmes top my favourites to watch as there are so many formats while the English chef's all have similar formats which can get tedious. Plus the Americans love a bit of sweet naughtiness in the creations!