The recent Crabtree nonsense has made me think of starting this thread. Sometimes it's the main character, sometimes it's a background player who steals the show whenever they appear on screen. Here's some to start us off.
Edmond Blackadder, Blackadder
Trigger, Only Fools And Horses
Victor Meldrew, One Foot In The Grave
Officer Crabtree, Allo Allo
DI Derek Grim, The Thin Blue Line
Henry Davenport, Drop The Dead Donkey