Batman

Some of the best Batman trade paperbacks to start your collection with are:

Batman: Year One by Frank Miller
Batman: The Dark Knight Returns by Frank Miller and David Mazzuchelli
Joker by Brian Azzarello and Lee Bermejo
Batman: War on Crime by Paul Dini and Alex Ross
Batman: Black and White volume 1 - short stories by many great comics writers and artists
Batman and Robin volume 1 by Grant Morrison and Frank Quitely