So I picked up a bunch of Batman freebies. I'm not a huge Bats fan. I really only read him when Catwoman shows up because she's awesome.
DCeased is basically the DC universe vs. zombies. It's an interesting idea but I didn't find it particularly "must know what happened next".
The Batman Black & White series are short Batman stories. Somewhat Noir in feeling, sometimes by people associated with the cartoon series. An Innocent Guy is the best one because it actually uses something I think some villain should have done before.
The Batman Adventure one features Batgirl. It's entertaining, but Batgirl is drawn in such a way that she would have no room for a stomach.
(I believe most if not all, of these are still free for kindle).