German phrase
Welcher ~ gefällt Ihnen am besten?
Meaning
Which ___ do you like best?
When to use it
It asks for your top choice. It is polite and suits formal conversations.
Example dialogue
Welcher Studiengang gefällt Ihnen am besten?
Which degree program do you like best?
Am besten gefällt mir Informatik.
I like computer science best.