sort of in order, Blueprint For Murder, Ego is a selfish dumb reason to murder Bo. Bo was going to cut off his funds for his "Vision".

The Most Crucial Game, I still after seeing this a hundred times, I can't see a real motive for Hanlon to murder Wagner.

Forgotten Lady, selfish over her fame.

Make Me a Perfect Murder, Kay murders Mark because he won't put her in charge after he goes to New York, selfish.

Columbo Cries Wolf, Sean (eventually) kills Dian because she will take away his playboy lifestyle after selling the magazine

what are your thoughts?

Goes to College always stood out to me.

Luis Montoya has about the most "melodramatic" reason, since it's hard to say how much the business with the bull would have hurt his image. And besides, Hector was probably going to keep his mouth shut just as he promised.