Like other shows like House, the Mentalist, Lie to Me etc, it really doesn't come down to the situations they get in, but mostly just how interesting the main character is to watch, and see how they come to their conclusions. I think Walter is a pretty fresh take on the archetype.
I hope it doesn't get cancelled :(
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The batman villians all seem to be one big joke that batman refuses to laugh at - SantaRPG