NOTE: These rankings are only my opinion, obviously, as with rankings in sports, there will be lots of comments and critcism to what follows. I mostly based the rankings off of the importance of how each of the physicists advanced the field of physics, which every person here has done greatly.
Albert Einstein
Isaac Newton
James Clerk Maxwell
Paul Dirac
Niels Bohr
Werner Heisenberg
Galileo Galilei
Erwin Schrodinger
Stephen Hawking
Richard Feynmann
Ludwing Boltzmann
Nicholas Copernicus
Max Planck
Robert Oppenheimer
Louise de Brogile
Wolfgang Pauli
Archimedes
Stephen Weinberg
Enrico Fermi
Vera Rubin
Ernest Rutherford
Max Born
Roger Penrose
Subrahmanyan Chandrasekhar
Peter Higgs
HONORABLE MENTIONS (in no particular order): Nathan Rosen, Hugh Everett, Michio Kaku, Lord Kelvin, Michael Faraday, Sean Carroll, Alan Guth, Johannes Kepler, Robert Hooke, Boris Poldosky