Okay, I'll start.
How to Do Lex Luthor Right
Alright, Goyer, pay attention.
And to those who think Brainiac or some other such is Superman's ultimate archnemesis, just move along. You probably think Bane is Batman's ultimate archenemy and Venom is Spider-Man's. So, yeah, you can have that.
Even once we get to the place where we acknowledge the last 60 years of comics and adaptations where Lex Luthor has been Superman's greatest enemy, there are still some problems. Most notably: Lex is played out. We've seen him in every other live action Superman movie, and a shell of his actual greatness at that. So... for adapting Lex into the MOS Universe, there are three simple rules, detailed below.
1) Make Lex Intelligent
Now back in the 50s this meant mad scientist, and that was cool then. In the 80s this meant a powerful businessman. But what does that mean today? Well, the smartest guys we know in fiction are people like Sherlock Holmes and James Moriarty, people like Tony Stark and Gregory House. A big part of modern intelligence is the ability to quickly analyze situations and understand non-obvious information. Then to use this to stay three moves ahead of everyone else. Portraying that analytical side of Lex is crucial. Adding a corporate empire with a powerful applied sciences division makes a great deal of sense, but unless Lex is able to size up Superman is seconds, even deduce his secret identity, then he loses some appeal. He should immediately go beyond the need to kill Superman, but to something more insidious, more destructive. Like Joker, he should be after nothing less than the heart of the city.
2) Make Lex dangerous
Leave the world of real estate behind, obviously. But more seriously, in keeping with modern intelligence, where being an inventor of one really cool thing with a lot of applications is a lot more endearing and realistic and truly intelligent than having the magical power to conjure pseudo science out of nowhere. What Lex makes could be any number of things. Perhaps harvesting the power source of the Kryptonian ship to create a Kryptonite reactor in the heart of the city, deadly to Superman? Perhaps his goal is to get Superman to cross that line (again), and show the world what a dangerous monster he really is. Perhaps he has a satellite laser he can drop whenever he wishes.
Naturally he should be paired with some other villain that has more of an arc, much as Joker was paired with Two-Face. That villain could be Metallo, or it could be Brainiac, just depending. But more than the physical threat, Lex Luthor should be able to reach out and touch Superman any time he chooses. He should have the keys to the man's house, be close with Lois, he should own the Daily Planet, and give Ma Kent a new house. He should be intimately in contact with Clark's entire life. And he should be untouchable, not just in having some Kryptonite on him or some such foolishness, but beyond that, never giving Superman a reason to confront him physically.
Though, I do see him somehow putting Superman back into a Kryptonian environment and going mano-a-mano at some point, that could be fun.
3) Make Lex fascinating
This is the hard part. This is what sets Joker apart from everyone else. This is where we take this idea of this egotistical malevolent businessman and we turn it on its head. You might need to get really creative with the casting to find a performance and an adaptation of the character that is truly fresh.
The crucial parts of making a character like this interesting is a) adding an impenetrable layer to him. Lex isn't after power, neither is his background known. He fell off the map for 5-10 years and now he's back, and his experiences are simply unavailable. Now he's here to apparently make people stand up for themselves, and make themselves better instead of relying on this superman... but at the same time, you realize that this person is a sociopath, and really might do anything at any time, and even he doesn't really claim his stated goal.
The second issue is B) Giving him some eccentrism. Something that contrasts with the typical evil corporate villain. A stirring martial arts workout regimen. A sick daughter. A predilection for extreme sports like skydiving. A heavily sarcastic wit. A dozen copies of the same exact custom designer suit. All of the above? Something that makes him not at all normal, even on the surface. Combined with an impenetrable layer can make Lex truly Fascinating.
Extra Credit) Play him against Superman.
This one's obvoius, but Superman and Lex are opposites. Superman is a physical powerhouse, Lex is not. Superman is an ideal to strive for, Lex is purely greed and survival instinct. Superman is from a small town, Lex form a big city. Superman is young dashing and handsome, Lex is older, reserved and a bit scary looking at times. Superman comes from above, Lex from below. Superman has no social power, Lex Luthor has all the social power. Superman is seen as a danger to society, Lex Luthor is seen as a necessary part of daily life. Superman is a good guy, who occasionally does bad things when absolutely necessary to do the most good. Lex Luthor is a truly bad guy, who does good things only when absolutely necessary to do the most harm. Superman cares about everyone, Lex cares about no one but himself. These comparisons go on, and on, and on. Play them up, to the max. The better the villain, the better the story.
So what say ye? Any thoughts?