kitchen nightmares is the best because its the most real... its real families in real struggles and this old guy comes in and kicks them upside the head and says "hey, this is GOOD STUFF if you want it to be".
kitchen nightmares is good too because they are real professionals all competing for one really good job. fox can dolly it up as much as they want, you can still easily pick out the real emotion from the contestants. the show is also a really good learning tool for those who want to know how to succeed in any higher end job too.
master chef is a trainwreck. its american idol without the idol part. at least with ameircan idol these people actually get to be idols, even if their fans are weird. this master chef winner will be forgotten about in less time then time moves itself.
but if you think about it ramsey's point of view, he now has 3 shows for 3 different types of audiences... "smart businessman" is the first thing i can think of.