I never understood the fascination with Sinatra. Maybe if I had been to one of the Vegas shows or night clubs when he was performing I might get it. He never seemed cool to me.
My list of cool from the pre-hippy sixties:
1. John Wayne
2. Sean Connery
3. Dean Martin
4. Robert Mitchum
5. Humphrey Bogart (I know he was dead by then, but his movies lived on)
Liked the western (one or two???) with Duke Wayne and Dino.
William Holden was pretty cool in Stalag 17.
Steve McQueen and Clint led into the 1960s. I also liked James Garner who could also play comedic roles with Doris Day.
Have you ever seen him with Gene Kelly and Kathryn Grayson in Anchors Aweigh when he was young? I think he was great. I have no clue what he was like in his personal life back then, but he was pretty good on the silver screen, IMO.