I am also big fan of Byomkesh Bakshi.. He was someone who came closest to Indian version of Sherlock Holmes and I enjoyed watching it over and over again.
The intelligent dhoti-kurta clad Rajit Kapoor aka Byomkesh, who solved the most complicated cases. K K Raina as his assistant was Watson's counterpart in the show, who helped Byomkesh in every mystery he investigated.