I've read that the Ultrascope is great for breath sounds, but not good for bp's. The majority of people seem to prefer Littman, but don't specify which model, or why they prefer it.
I'm in the market for one. I don't want to spend more then $100, considering how easily it can be lost or destroyed in this profession.
I've found some tips through googling (feel free to add your own):
-rubber ear pieces provide better sound
-thicker tubing provides better sound
-dual tubes might rub together distorting sound
What is your stethoscope of choice, and why?