I am a Marvel fan, that is obvious. While I don't necessarily care much for DC, I don't hate them. I do like The Flash, Batman and a few other characters that aren't Aquaman (sorry, I had to say it). That being said, DC is coming out with their own cinematic universe which has me intrigued. Between Man of Steel and DC teaming with NetherRealm Studios to make, Injustice Gods Among Us (It being from that developer for me pretty much guaruntees that it's going to be amazing). I've been in a DC mood lately. Here are certain things I want in the DC Cinematic Universe. Actually, I'm gonna start calling it the DC Nation. I know it's what their doing with their shows but, I'm doing that to seperate from Marvel.
Red Hood Storyline

I know this would be mimicing Captain America but, I think if you introduced Jason Todd in the first Batman. Then, in Batman 2 you could have the Red Hood storyline. I'm not talking full fledged adaptation (which would be cool) but, have all the major, main details and characters from the story into the film. I don't know about you but, I would really like to see the Red Hood in the DC Nation.
Green Lantern Reboot
I was debating on whether to reboot Green Lantern or go with a sequel. I was leaning more towards a sequel but, there is nothing they can do to redeem the first film except reboot it. But, I was thinking of keeping Hal Jordan. If they go with rebooting Green Lantern, Justice League could be that film. It could be what Batman Begins was for Batman and what Man of Steel has potential to be for Superman. It's not that Reynolds was bad. The movie just all around sucked major ass. I would pick Rijan Johnson for Green Lantern because of his film, Looper. He showed he can direct action/sci fi while also making a VERY good film. If you ask me, he would be the closest to a perfect Green Lantern director as you can get without going to Ridley Scott.
Aquaman film
For as much as I laugh at the idea of Aquaman being made into a film. It would also be doing fans a great disservice to not make an Aquaman film for their DC Nation. From what I hear, as long as they adapt the New 52 version of him, the film would be badass. But, for me personally, I'd wait until "Phase" 2 or 3 of the share universe before I'd introduce an Aquaman film. It just sounds as silly as Guardians of the Galaxy (which everything but the concept of a talking tree has grown on me). If they make this how they made Avatar but mix it a little bit with the story for Thor. Then, it probably won't be half bad.
Team of five or 6
For a debut Justice League film, I'd stick with six or five character roster. Preferably: Superman, Batman, Wonder Woman, The Flash and Green Lantern. That's my ideal line up for a debut Justice League film. But if I were to add one more, it would be Martian Manhunter.
A more serious tone
I don't mean this in the sense of more serious superhero movies being all the rage these days. I mean it in the sense to seperate themselves from Marvel. Marvel are fun, family orriented films. While DC has always been for a more "mature" audience. So, they're films should be a little more serious than Marvel.
A damn good Wonder Woman film
I did my research on Wonder Woman and I am still confused about her and her mythology. If we were to get a Wonder Woman film, I want a damn good one. Which means, a director (well known or not) to direct and a actress who they got for her acting ability. Nicolas Winding Refn has expressed interest in a Wonder Woman flick. Again, I don't know much about Wonder Woman but his vision has at least gotten my attention. Maybe he could do fit for her. After all from what I hear, Bronson and Drive are both suppose to be excellent films.
Barry Allen Flash
I've always prefered the Barry Allen version. Not to mention that he is The Flash of the New 52 and that's what they are apparently basing their films off somewhat of so, why not? I think Barry Allen would be the best way to go for Flash for a feature film adaptation anyways. Do you want The Flash to be taken a little more seriously or being a "jerk" like what most people think of Spider-Man to be in The Amazing Spider-Man?
Detective and Gritty Batman
This could be what I am calling the "The Incredible Hulk" meets "Sherlock Holmes" of the DC Nation. What I mean by Hulk meets Holmes is, Batman being a fun, gritty action flick while the character uses his detective skills to help him throughout the film. Which I think would be the best way to separate itself from the Burton/Shchumacher films and The Dark Knight trilogy. My choice of first villain either The Riddler or Mr.Freeze. There are kids my age who don't even know those two outside of the Arkham games. Then again, I'm the only comicbook fan I know personally but still. Those two would be my first choices for a rebooted Batman.
Sinestro Corps War
Wait until "Phase" 3 for this one. But, this could be the "Star Wars" film of the Green Lantern franchise. Just one huge epic movie. If I were working at DC and Warner Bros. This would be the film to start "Phase 3" so we get a basic idea of where the tone and everything is before the next Justice League film.
I know a lot of this, people have already stated is needed for a DC Cinematic Universe or DC Nation. But, I decided to give my two cents. Comment below and be respectful please.