While Frank Gorshin is more famous as The Riddler of 60's Batman I think John Astin's portrayal as Riddler was more accurate to the character. Like Jim Carrey's portrayal, Gorshin's was more in line with a Joker-like personality. Astin's was more mental which is the criminal's trademark, going so far as to being prepared for a Batclimb into his window. This to me makes it clear that while not as loved as Gorshin, Astin was ahead of his time and better in tune with the spirit of the prince of puzzlers.