Perhaps the most classic example of Columbo not being intimidated is in confronting his own phobia and putting it aside, such as in "A Stitch in Crime". Despite his horror around hospitals and watching surgical procedures, he is right up there keeping his eye on the valve replacement operation when closing in on the murderer.

Columbo faces-down another phobia early on, when he rides in a small airplane with the killer (who uses the opportunity to torture him, sort-of like Eddie Albert does on the boat in "Dead Weight"). And there are at least a couple of episodes, starting right with "Prescription:Murder" I think, where Columbo allows the killer to falsely believe he is "off the case" (allowing the killer to gloat over his own "influence" downtown), while of course Columbo never gives up.

But in terms of not being intimidated, probably the 2 best examples are the way Columbo lays his job on the line in "A Friend In Deed" by pursuing his own boss; and his enormous risk of humiliation in digging-up a huge building's foundation, twice, in "Blueprint For Murder". He braved similar public embarrassment later in "Columbo Cries Wolf". Columbo definitely has...well, instead of getting anatomical, let's say the courage of his convictions!

In "Prescription: Murder", "Suitable for Framing" and especially "A Case of Immunity" pressure is put on the L.A. Police Department to have Columbo ease up. In the first two examples the higher-ups collude with. Columbo to give the impression that he is off the case, but they keep him on.

In "Immunity" however, Columbo is told flat out that even if he's sure who the murderer is the federal government doesn't care! Despite explicit orders to stay away from the legation he still goes there during an important diplomatic function, allegedly to personally apologize. Could you imagine being an important diplomat and this shabby local cop shows up AGAIN while the King himself is visiting? He even eats some of the King's specially prepared food. It's outrageous behavior and to me it's the ultimate example of Columbo not being intimidated. Of course we later find out that he secretly contacted the King, but probably not before that party.

Also there is "Identity Crisis" where once again the federal government steps in and explicitly tells Columbo to back off. And once again Columbo ignores them despite the Director of the CIA personally flying in.

Columbo had cojones.

Great post, Pete! You ended with exactly what I didn't quite say, but meant.