Actually, there's almost nobody else remotely like Feyerabend. Imre Lakatos came close, but was more interested in mathematics than science. Feyerabend was one of the most brilliant and original thinkers of the 20th century, whether or not he was right about some things, or about anything at all.
Lakatos was a great philosopher of science, while Feyerabend is a gadfly. His "Proofs and Refutations" doesn't really hold up -- once mathematics reached the modern standard of rigor the process he described stopped -- but his notion of progressive versus degenerating research programs is very powerful.
I knew Feyerabend in Berkeley in the early 1960's. He was an engaging character, a large personality, a brilliant conversationalist, always surrounded by an interesting collection of other articulate people as he held forth at the Mediterranean Coffee House on Telegraph Avenue. Right or wrong, his perceptive observations motivated further consideration.
