Did you ever notice that some of the charachters on The Simpsons you never really see them in a situation together. It's usually the ones who have very similar personalities. Here are a few examples

Ned Flanders and Professor Fink

Barney Gumble and Comic Book Guy

Ralph Wiggum and Rodd and Todd Flanders

What are some other ones that you guys can name off?

martin and rod and tood flanders

how are those characters similar?? @_@