Callers who are not named as regular callers, but whom I almost always enjoy:
JonfromMaplewood
Mackro from Seattle
The Frank from Weehauken/Mike from Manhattan dynamic duo
Christina from Brooklyn
He was short-lived, but I also enjoyed the guy who tried to explain various Mexican foods to Tom.
I'm sure there are others. You all make a nice break from the mutants, who are only funny in Tom's reaction to them.