None of the shows you mention are true "reality" shows. Rather, some are true game shows and others are contrived - scriptless but none the less nothing like true reality.
"Survivor" is still getting decent ratings although you would expect a fall off after 20+ seasons. The producers continue to tweak the "rules" and contests and have now resorted to occasionally bringing in previous contestants (or their relatives) to try to spice up the competition. It's pretty lame but still the best of its genre.
"Amazing Race" is much less entertaining and has the ratings to prove it. It reminds me a lot of the old "Honeymooners" show where Alice and Ralph just shouted and screamed at each other for 30 minutes. Unfortunately, AR is an hour show so much more screaming.
The only thing that remains completely interesting to me is where do the above shows get their contestants? Seems a lot of them have idle time on their hands despite being described as "professionals" of some sort (doctor, lawyer, indian chief). Both shows seem to have some sort of formula for setting up tribes....er, teams. You can almost label them before the season begins.
I can't, for the life of me, understand how anyone with more than two operational brain cells can watch the other two. "Biggest Loser" reminds me of the old circus freak shows (bearded lady, guy with three arms etc.). "Extreme Makeover" is virtually as bad. It's probably not a good idea to watch these two shows with a loaded gun on the premises because either you, or your TV set, is going to suffer.
