It is not to my personal taste, but I think Paul's "Mull of Kintyre" remains the top-selling commercial single in the UK. That has to rank. "Say Say Say" may be royally hated by many, but you can't argue with its worldwide popularity. "Silly Love Songs" practically defined the summer of '76. After that, it gets into personal taste. "Wanderlust" and "Calico Skies" are gems that nobody knows, in fact, half of "Tug of War" is great imho. "Band on the Run" was his post-Beatles highlight, but I don't think that's the only great thing he's done in 40 years, that's setting the bar a little high for any man or act.