Bergerac was always my favourite. Death in Paradise (Kris Marshall). Rock Hudson in MacMillan and Wife (who knew back in those days?) Rupert Davies in Maigret.
So hard to choose as there are/were so many, but I did have a soft spot many years ago, for Frank Cannon, played by the lovely and cuddly William Conrad. Also quite liked Callan, played by the wonderful Edward Woodward, who was also a fantastic singer.