I would actually recommend getting your friend a gift certificate instead of trying to pick one out for her. The ear pieces of each style and brand fit very differently. We have several different kinds at work and some fit so snugly, they totally plug my ears and I can't hear the blood pressure.

That being said, I've had a Littman Classic for years and have had no problems with it.

I scouted around and could only find one stethoscope made in the US, if that matters to you:

http://ultrascopes.com/about/ultrascope-models/

I'm pretty interested in these, not only because of the nifty designs but because they seem to be useful for noisy environments - the definition of my workplace!