Good about in A Friend In Deed when Columbo admits to Mrs. halperin he was drunk at the Christmas party.
There's the cast party in Dagger of the Mind, with its stereotyped English theatre people. (I mean stereotyped in an entertaining way, like most of the characters in that episode.)
A Deadly State of Mind. When he’s sitting with the doctors and explaining the case he’s working on.
I can't help thinking that a character played by Danny Wells could make any party a good one to attend.