I can't even pick a favorite album let alone song. Here's my top 10 from the ones released in the US.
Cat 1 - Sgt. Pepper/Abbey Road
Cat 2- White Album/Magical Mystery Tour (except Flying and Blue Jay Way)
Cat 3-Rubber Soul/Revolver
Let it Be
Beatles for Sale
Hard Days Night
Help!
I guess I lean towards the later stuff.
Band on the Run and Venus and Mars would displace a couple of them.