Physics Department
Only a handful of people major in physics, but they get to use facilities like I. I. Rabi's plush office in Pupin.
Once included Manhattan Project Nobelists like Polykarp Kusch, I. I. Rabi and Enrico Fermi; now has Nobelists TD Lee and Horst Stormer (who is actually joint with Applied Physics and Applied Mathematics in SEAS).
In case you were wondering, Brian Greene is actually a math professor.