At this time of year we are frequently asked this question.
When I started on my clinical training 27 years ago the medical school that I was at (Liverpool) recommended the Littmann Classic SE stethoscope. I still have that Littmann classic that I purchased 27 years ago and it is still a great stethoscope. When I was in my final year I purchased a Littmann Cardiology as I felt the better acoustics would help me in my final exams. I continued to use that stethoscope throughout my medical career, and I still have it, and yes you guessed it is still a great stethoscope.
For medical students starting their clinical training the Littmann Classic 11 SE stethoscope is still the recommended stethoscope and offer great value for money at just £45.90 (net VAT)
For those who want to push the boat out a bit more and for medical students in their final year the Littmann Dual 111 Cardiology at £103.99 (net VAT0 is a superb Littmann stethoscope. It is extremely robust, and will stand a life time of use