The Greatest

Inspired by Clifford Johnson's Newton vs. Einstein post over at Cosmic Variance, I want my own little "greatest" contest.

A young friend of mine who is a grad student at U of New Mexico was telling me about going to the regular seminars that Murray Gell-Mann comes down from Santa Fe to give. He added that he had stopped going because G-M was too bitchy or something of the sort. I said: "Don't stop going - he's the greatest living physicist!" Are there even any other contenders? Suggestions welcomed, but will likely be met with an argument!