A pretty cool actor who managed to play off parts of his Columbo character into a couple great Neil Simon-written comedies: The Cheap Detective and Murder by Death, the latter is on Netflix streaming. In both, Falk plays Sam Spade parodies. I highly recommend both if you can catch them via TCM.
He also dovetailed his BS’ing skills effectively on Alan Arkin in the original version of The In-Laws. Don’t waste any energy with the re-make starring Albert Brooks and Michael Douglas.
Lastly, Peter will be immortalized by numerous generations as Grandpa the Narrator in The Princess Bride one of the greatest flicks made in the Eighties. Even while reading the novel, my brain puts his voice to the words.