From my knowledge:

Hey Jude- stayed on the charts the longest,

I Wanna Hold Your Hand- was their biggest hit on the charts overall,

Yellow Submarine- is usually the one instantly thought of when their name is mentioned to someone mesions them to anyone,

Strawberry Feilds Forever- when you combine all the critic’s lists, this one comes out on top,

“A Day in the Life” or “Hey Jude”- seemingly wins out when you combine critic’s and reader’s lists

I tend to think it’s “A Day in the Life”, because of my previous statement, and it’s considered the big one on SGT. PEPPER, which, in turn, is considered their magnum opus, generally. It all sounds very technical, I know, but any thoughts? Personally, my favorites “Revolution”, “A Day in the Life”, “Dear Prudence”, and “You’ve got to hide your love away.