and i agree about Gauss, SN Bose is a personal favorite of mine, otherwise Gauss most likely would take that spot.
as for my bias towards Bose, mostly because he is largely unknown outside of the physics circle. yet he was very brilliant. aside from Bose-Einstein Condensation Theory and "Bosons" named after him, he is still largely unknown. Yet, he was one of the pioneers of statistical mechanics. My bias comes from the fact that he is from my country and was a lecturer at my local university.
there is a famous story about him, at a particular physics conference, Bose was sitting in the first row, sleeping, while Planck was trying to explain a theory with some equations. He wasnt having any luck making the laymen understand what he was talking about, and he noticed Bose was sleeping. So he said, "Pehaps Professor Bose could explain things a bit better!"
Bose walked up right away, solved the equations simply, explained their meanings to the audience, walked right back, and fell back asleep.