I’d like to read your opinion of how the Penguin would fit in the Nolan Batman films, and whether you believe Nolan’s determination not to use the Penguin is wise or closing himself off from a potentially interesting story.
Yes and no.
On the one hand, I share Tim O’ Neil’s opinion that the Penguin is one of Batman’s best villains (although I would personally give pre-eminence to the Riddler, but ultimately “best Batman villain” always comes down to what aspect of Batman you like best, and I like Batman best as a detective) simply because the Penguin isn’t crazy; he’s just a straight-up crook. That might not be as otherworldly and scary as the usual Arkham gang of horrors, but it can make for a great villain because the Penguin is just a bastard, plain and simple. No stupid self-destructive plots, no monologuing, no movie-style villain tropes. The Penguin would make a great villain in a Nolan Batman movie…
…except he probably wouldn’t. Because all of the things that the Penguin isn’t are what’s mostly expected out of a Batman movie now: the Bat-villain in a movie has to be crazy-go-nuts because it has becomes received wisdom that Batman’s Enemies Are Crazy. This goes for the comics too, of course; it’s one of the reasons Penguin has generally dropped down the ranks over the past two decades, demoted to basically being a mob boss. But it’s even moreso in the movies, where Nolan is especially interested in the dark theatricality of Batman and his enemies. Nolan’s Scarecrow is obviously insane long before he ever gets dosed with his own fear chemicals; his Ra’s Al Ghul is a weird blend of totalitarian and guerrilla. Part of what makes the new cycle of Batman films tick is that the films explicitly say that the only sane response to this insanity is a different type of insanity. But the Penguin isn’t insane. He’s just a criminal; nothing more than another version of Carmine Falcone, who gets shoved out of the plot halfway through Batman Begins.
Besides, how do you do a “realistic” Penguin? What makes the Penguin a good comic character are those explicitly comicky bits: the trick umbrellas, the monocle and top hat, the birds as weapons. That’s all stuff that won’t fit in a Nolan film; without it, all you’ve got is a pretty bog-standard deformed criminal. Danny Devito’s Penguin in Batman Returns was great (and Returns is far and away the best of the 90s cycle of Batman movies: the best action, the best acting, and the only one that doesn’t feel tremendously dated now) precisely because in addition to being a nasty piece of work he also went in for all the crazy gimmicks. But all that won’t fit in a Nolanverse film, because if you don’t start out crazy in the Nolanverse, there’s no good reason to play dress-up.