This is a recurring question from medical students just about to embark on clinical studies, and from their parents who often wish to buy a stethoscope as a gift.
If you can afford to opt for a Littmann Classic 11 SE Stethoscope as this is the stethoscope that most medical students in the UK will use, and that most doctors trained with, and many still use in their everyday clinical practice. At around £50 it offers excellent acoustic performance, at an affordable price. It also comes in a huge array of tube colours & finishes, which means their should be one that suits you.
For final year medical students a Littmann Dual 111 Cardiology stethoscope at around £108 plus VAT, can be a good choice as it can help them in picking up heart murmurs during their final exams.