After watching quite a bit of the 60s show, I came to this conclusion. Now, this sounds absolutely crazy but bear with me:
He doesn't hide in the shadows: Adam West's Batman is not called the Bright Knight for nothing. He is perfectly willing to face his foes in broad daylight under a bright, blue sky if necessary. "Darkness is your ally" most definitely does not apply to this Batman. Also, notice how he never sneaks up on his enemies. He doesn't hide in the rafters above, swinging from gargoyle to gargoyle or perform bungee-jumping, hit-and-run stealth attacks. No, he just charges straight in and announces his presence. His entire style is basically just "Here I am, now bring it on".
His costume: It looks ridiculous and that's the point. He doesn't wear thick, bullet proof, super Hi-Tech advanced battle armor. Instead, he wears something that looks like a bargain basement Halloween costume. Like something only a lunatic would run around in. I won't lie, if I was a criminal and saw a guy in the full light of day, heading towards me in this getup, proclaiming me under-arrest, I wouldn't laugh. Instead, I'd be extremely unnerved. I'd think, is this guy mentally all there? Maybe I'd better take him seriously. Who knows what he might do If I don't?
He never, ever, (unless it was in an episode I didn't watch) loses his temper. Honestly, that's probably that's probably the most intimidating part for me. Someone who is completely calm at all times and never raises their voice would unnerve the hell out of me. I'd probably be walking on eggshells around them, in anticipation of the very thing that would cause them to finally snap.
Thoughts? As I said, probably controversial, but interesting to see what others think.