This show has been subject to an unfair lack of recognition. The only times I hear anything about it is when some discusses the career of the late, great Bruce Lee.
I blame the executives at ABC at the time of the show's broadcast. When they approved the show for broadcast, they no doubt expected another light-hearted, camp heavy show, like Batman. What they got was something that was mature, well written, and is not looked upon with contempt or mocking laughter by fans of the original character.
If they show had gone one for at least one more season, perhaps more, then it would have left a bigger impression on the minds of the viewing public. Instead, it became one of the many shows that lasted one season and gained a cult following that those who have never seen it are unable to understand (like the great Joss Whedon show Firefly).
If you haven't seen any episodes, track some down and give it a shot. Your fears of Batman like neon-camp will be quickly laid to rest and you will likely find yourself wishing for more adventures of The Green Hornet and Kato.