Who Was the Most Famous Musician in the Beatles?

They are all very famous, but I'll probably go with Paul McCartney, as he is still alive and performing. Younger music fans are more likely to know him through his collaboration with Rihanna and Kanye West than his work with the Beatles. Next year it'll be 40 years since John Lennon was murdered, he is likely to be a less significant figure to most people born after 1980.

Who do you think and why Emily?

I agree with ACR. Paul is still going on strong and we frequently still hear about him. Ringo is also still alive but we don't hear about him anymore. The other two were very successful back in the day but have since passed.