I think all of these countries are safe for Americans to visit. I have been throughout Europe (though not Turkey) on both business and pleasure and have never experienced blatant, or targeted anti-Americanism. In fact, my experiences have been most welcoming from just about everyone I have met.
The key in visiting any country is to be respectful of the people and its culture and to not assume that they should go out of their way for you because you are an American. Also, I wouldn't do anything to make yourself stand out or flash money/jewelry to make yourself a vicitm of petty crime.
Have a great trip!