I strongly suggest every Batman fan to buy the book : Penguin - Pain & Prejudice.
So far, it has been the best portrayal of the Penguin that I have ever seen.
It manages to make a believable fusion of all the previous versions of the Penguin (gothic freak, hidden weapons designer, criminal mastermind, mob boss, birds control, ...)
Even better, the Penguin's core personality is well explained :
True strength is not about muscle, size, looks ... it is about strategy, persistance, determination and to get back on your feet after being humiliated.
If the storyline follows this road, Penguin could become one of Batman's greatest adversaries ever.
That's my personal favorite.