This one's easy for me. "Lovely Rita." Perhaps it's the opening guitar notes, or the "ahhhhhh" at the beginning that sounds like a man standing on the highest hills of the world about to declare his newfound love, or the instruments that at times sound like a conniving feline twirling its whiskers, or the piano solo, or the fact that it is such an unlikely love song (you gotta love a story about a guy who's smitten with a meter maid, and not a beauty model), or the fact that I can picture Paul "sitting on a sofa with a sister or two" (and I can't tell if they're laughing, or just staring at the wall in silence, but it doesn't matter), or how EVERY time I listen to it, it makes me feel so happy. I think it's one of their most overlooked songs. I'm gonna listen to it right now.