Personalized cover letters are nice.
We sometimes have people take the attempt a little too far, though, and list every name in the masthead:
"Dear Mickey, Minnie, Goofy, Pluto, Donald, Huey, Louie, Dewey ... [and the list goes on]"
It's harmless, of course, but it always strikes me as so awkward that you just kind of have to laugh.