Brought to us by the same team that gave us "Batman," here was a show that went above and beyond a Batman knock-off.
Similar to Batman (The Dark Knight, not the campy version played by Adam West) and Spider-Man in some ways, The Green Hornet was definitely a hero in his city, but almost no one saw him as such. A crime fighter who preferred to be viewed as a criminal, he used this position to gain credibility with real criminals. Often infiltrating gangs and becoming an associate, he would of course turn on them, striking quickly and leaving just as fast, making it look as if the soon-arriving police were responsible for the bust, thus letting Hornet remain a "criminal" to infiltrate even more rackets. No one really knew what side he was on, and so many took a chance in letting him in. Along the way, he is aided by his servant/bodyguard Kato (played by Bruce Lee), the district attorney, and his secretary at The Daily Sentinal, the newspaper he owns. These are the only ones who know that Britt Reed is really The Green Hornet, a great hero.
As opposed to the series Batman, this one was very dark. The plotlines involved murder and other things that would never have been addressed on Batman. The action was much more realistic and violent, the scenes were dark (often taking place at night), and the acting was more intense. There were definitely some light and even goofy moments, but by and large, this was a very serious show.
There is, however, one outstanding similarity between the shows Batman and The Green Hornet; they both had great cars! Batman, of course, had the Batmobile, and Hornet had Black Beauty, a true rolling arsenal (in real life too; because of limitations in special effects, the car had real missile launchers in both bumpers!).
In conclusion, those expecting just another Batman-like show were no doubt disappointed, but those who stuck with it knew it was special. It's a shame that it's not more appreciated now, as it really was a well-written, exciting show.
P.S. I almost forgot to mention the great theme song; "Flight of the Bumblebee" as played by Al Hirt on trumpet. Many have heard it despite never having seen the show!