"I would like to be a villain, and I would really like to play the Riddler." -Jim Parsons
I want to see a Riddler that is an absolute genius and just wants to find an opponent worthy of the game. And as much as I dislike The Big Bang Theory and Parsons' geeky-squeaky voice in it, I DO think he could pull off a completely dark Riddler very well and would welcome seeing it done.
He would need to be smart, sophisticated, and deadly-as I wrote in an old post:
As for the villain? Set up a new trilogy in the Nolan-verse with the Riddler as the main antagonist. This wouldn't be the silly, wacky-zany goon of old. Mr. Edward Nigma would be an intelligent games master, not some fool obsessed with proving his intellectual superiority.
For the Riddler, he'd would have to be handled like he is in the Arkham video games- he'd leave riddles and traps strewn about Gotham City, but never, I repeat NEVER, be there himself. He'd be too smart for that. We need someone that is not only capable of beating Batman, but capable of getting away with it in plain site. So while The Riddler wouldn't be out and about, while Nigma could be seeded throughout the series, hiding in plain sight. And the kicker- he'd outwit the Bat. He would win. In at least the first two films- possibly even in the third.
During the Riddler's scheming, he'd send in others to do the dirty work. Maybe hiring small crime bosses like the Penguin and Black Mask to create warring factions around Batman to keep him busy and distracted while keeping his grand plans going. A man of Nigma's caliber would be controlling the chess board for the whole game. Competent and effective. Make him a bit older, show that he's been doing this for years. He's looking for a challenge- and Batman is it. The so-called "Dark Knight Detective."That's just how I think it should be done. A Moriarty to Batman's Sherlock, pushing his mental limits to their breaking point.