I am graduating in a couple weeks and I have updated to a Littmann Cardiology III
. It is fantastic! Sounds are so clear, especially compared with my Littmann Lightweight II SE that I used throughout nursing school. I like that the Cardiology III has adult and pediatric diaphragms. (Super convenient if you ever work ER). The pediatric diaphragm converts to a bell.
However, for school, I would recommend the Littmann Classic II SE at a minimum. This stethoscope is a quality scope without the cheap feeling of the Lightweight. You can buy the more expensive scope when you graduate and you wont have to worry (as much) about anyone stealing your stethoscope in middle of the semester!
I've tried my preceptor's Master Cardiology and it is truly awesome! It doesn't have a bell though, and your school may require a bell for health assessment class. The adult diaphragm is convertable to a pediatric diaphragm. It is about $50 more than the Cardiology III.
Whether you end up getting the Classic or the Cardiology III or Master Cardiology, I highly recommend getting a color other than black, burgundy, or navy. These colors are popular and attractive to people who may walk off with your stethoscope. Make sure you get a name tag or other unique identifier. If you get one of the cardiology scopes, you should also have your name engraved in addition to a name tag and colorful tubing.
As far as brands of stethoscopes are concerned, nobody beats Littmann and their warranty services