Nightwing 
Donna Troy 
Kon-El 
The Atom 
Wally West 
Cyborg 
Green Lantern (Stewart) 

Batman
Superman
Wonder Woman
Green Arrow
Wally
Hal Jordan
Aquaman or Black Canary

I actually just made a list of what I consider My Ideal Justice League Line-up (http://www.comicvine.com/myvine/or35ti/my-ideal-justice-league-line-up/75-32924/)  
 
Superman 
Batman 
Captain Marvel 
Wonder Woman 
Green Lantern (Jordan) 
The Flash (West) 
Martian Manhunter 
 
Them and another dozen reserves are on my list. The team should be powerful, iconic, and diverse (not necessarily in terms of race/gender but more in terms of power).

this already proves there is no continuity here because Hal Jordan was fired and his ring taken away from him 

Batman  
Superman 
Martian Manhunter 
Wonder Woman 
Dr Fate 
Flash Wally West 
Green Lantern John Steward

Sara/Babs had the best one. 

Martian manhuntter 
green Lantern 
Captain Atom 
superman  
Wonder woman 
barry Allen  
Aqua Man 
red tornato 
Batman 
green Arrow 
 
This was an awesome team.

mine would be: 
 
1. Batman [Bruce Wayne] 
2. Aquaman 
3. Zatanna 
4. Blue Beetle [Ted Kord] 
5. Booster Gold 
6. Captain Marvel [Billy in white outfit/Wizard Shazam] 
7. Deadman 
8. Flash [Jay Garrick]  
9. Firestorme 
10. Starfire
 
...this does seem more like a JLI

Dick Grayson 
Supergirl 
Wally West 
Donna Troy 
Black Lightning 
The Ray (Ray Terrill) 
Martian Manhunter 
 
So yeah, I'd like to see a team of mostly younger heroes take up the JLA flag, but that's just me.

Batman, Superman, Martian Manhunter, Flash, Green Lantern, Wonder Woman, and Green Arrow IMO. And if I could add one more it would be Zatanna.

Grants morrison's JLA will forever be the best. 
Superman 
Batman 
Wonder Woman 
Kyle Rayner (GL) 
Wally West (flash) 
Aquaman 
Martian manhunter 
Plastic Man 
 
don't get any sweeter than this IMO...

Here's a list I did. 
 http://www.comicvine.com/myvine/technoman/my-dream-jla-team/75-22773/

Maybe I am boring but I would have to go Batman (Bruce), Superman, Wonder Woman, Green Lantern (Hal), Flash (Barry), Martian Manhunter, and Aquaman

Sara's all girl dream team is FLAWLESS.

Ok here it is my dreamteam or the Best Justice League in my own opinion... 
 
Superman (The name say it all The powerhouse)
Batman  (The best detective The power of the intellect)
WonderWoman  (Do i have to say it again "the name say it all" The power of the gods)
Flash  (we always need a speedster The power of time)
Zatanna  (The power of magic)
Green Lantern (Hal Jordan)  (The power of will)
Crimson Fox  (The power of sex)

Superman - A must have 
Batman - Bruce Wayne, another must have 
Wonder Woman - the last part of the trinity 
Green Lantern Hal Jordan 
Flash - Wally West, lightens it up a little 
Aquaman  
Atom 
 
Exclusions: 
Martian Manhunter - His wide range of abilities if written correctly would make him unbeatable. The justice league  are there 'to combat a foe no single hero could beat, J'onn can beat most... 
Green Arrow - I see him as a more serious hawkeye of the team while bats is cap america, I would've liked to include him but I already had 7...

Superman
Batman
Green Lantern (Kyle Rayner)
Zatanna 
Hardware
Plastic Man 
Martian Manhunter

Here's a JLA I'd like to see:
Guardian
Knight and Squire
Steel
Artemis
Congorilla
Zatanna
Wally West
Martian Manhunter

Superman 
Batman 
Wonder Woman 
Hal Jordan 
Wally West 
Martian Manhunter 
Hawkgirl

Original seven for me.
Batman
Superman
Wonder Woman
Flash (Doesn't matter which one to me. lol)
Martian Manhunter 
Green Lantern (Hal Jordan of course.)
Aquaman

Grant Morrison's original line up. Batman, Superman, Wonder Woman, Aquaman, Martian Manhunter, Green Lantern (Kyle) and Flash (Wally). THAT was the big seven.

Red Tornado 
Firestorm 
Aquaman 
Superman 
Nightwing 
Wonder Woman 
The Flash 

If I were in charge of the DCnU I would assume that characters such as Bruce Wayne and Clark Kent started their careers in the Golden Age. While I like any lineup that features the Big Seven, I feel like the characters would probably have too much stuff to do to be part of the Justice League. My version of the Justice League is based on the idea that Wonder Woman formed the League as part of her mission to bring peace to man's world. Plausibility aside, i created the rosters to be diverse by species, race, and gender. Below is my roster for various eras:
 
Justice Society (1940s-Mid 1950s)
1. Wonder Woman (Diana)
2. Starman (Mikaal Tomas)
3. Plastic Man (Patrick O'Brien)
4. Dr. Mid-Nite (Beth Chapel)
5. Wildcat (Yolanda Montez)
6. Roulette
7. Red Tornado (Android)
8. Crimson Avenger (Jill Carlyle)
9. Black Condor (John Trujillo)
 
Justice League (Mid 1950s-1960s)
1. Wonder Woman (Donna Troy)
2. Miss Martian
3. Jemm Son of Saturn
4. Starwoman (Courtney Whitmore)
5. Jakeem Thunder
6. Element Woman
7. Sandman (Sanderson Hawkins)
8. Animal Man (Buddy Baker)
9. Elast-Woman
10. Mento
 
Justice League (1970s-Mid 1980s)
1. Wonder Woman (Artemis)
2. Plastic Man (Luke O'Brien)
3. Zatanna
4. Vixen
5. Bronze Tiger
6. Firestorm (Jason Rusch)
7. Bumblebee
8. Vox
9. Fire
10. Ice
11. Poison Ivy
 
Justice League (Mid 1980s-1990s)
1. Wonder Woman (Nubia)
2. Animal Man (Garfield Logan)
3. Raven
4. Windfall
5. Halo
6. Looker
7. Katana
8. Gloss
9. Jet
10. Cyborg
11. Gypsy
12. Vibe
 
Justice League (The Present)
1. Wonder Woman (Cassandra Sandsmark)
2. Mr. Terrific (Michael Holt)
3. Argent
4. Aztek
5. Zauriel
6. Bushido
7. Hero Cruz
8. Hot Spot
9. Sungirl
10. Persuader
11. The Disruptor (Angelica Smith)
12. Anima

While it's hard to argue with the Big 7, and i do enjoy the new line up with the addition of Cyborg, I think my team would be: 
  
Superman 
Batman 
Wonder Woman 
Green Lantern (Hal) 
Flash (Barry or Wally) 
Aquaman 
Captain Marvel (Billy)

Superman 
Batman 
Wonder Woman 
Aquaman 
Flash 
J'onn 
Hal Jordan 
if you have to stick to 7 
but the JLA always worked best with a soft roster 
so let's add 
 
Power Girl 
Captain Marvel 
Zatanna 
Firestorm 
Vixen

Superman, Batman, Wonder Woman, Flash (Wally West), Martian Manhunter, Green Lantern (Kyle Rayner), Aquaman with Atom, Mister Miracle, Orion, Big Barda, Steel and Connor Hawke as additional members.

Superman - big gun
Flash (Barry Allen) - he is the speed force right? recon, experience, leadership material
Ion (Sodam Yat) - Cosmic aspect, Oan battery database, big gun
Captain Marvel (Batson, preferably as Lord Marvel when he replaced Shazam) - Magical side, big gun
Captain Atom - timestream knowledge, very big gun
Red Tornado - every team needs a robot that creates tornados
Firestorm (Ronnie Raymond) - for all the molecules out there
 
My idea is based upon superhero teams always being filled with powerhouses. Personal preference, I suppose.
I guess being so powerful they'd clash alot also, making for a greater dynamic within the team.

Well now that they scrambled our world, we are going to have to see how this new continuum fleshes out.  But there were so many deserving the chance at being on the League.  Now I love team books more than I love character books. The question is, who deserves and has earned  the right to be  on Justice League.   We have the big 7 plus Zantana, Red Tornado, Black Canary, Vixen, Dr. Light, Firestorm, Elongated Man, Green Arrow, The Atom, Black Lightning, Hawk Girl, Hawk Man and Captain Marvel,  these characters have served with honor. Then you have 3 other Green Lanterns, plus the JLI squad of Captain Atom, Booster Gold, Blue Beetle, Fire, Ice, Power Girl, Rocket Red. Then you have the Titans, Nightwing, Troia, Cyborg, Firestar, Wally West, Jade, Beast Boy, Raven, and Arsenal who have proven they are ready for the big time, in the case of Beast Boy and Raven they have so much potential, but the writer refuse to bring it out.  Then from the Outsiders you Metamorpho and Geo Force.  I have watched these characters grow and mature some for the last 30 of my years and not get to see them at the big dance is a shame.  How big should the league be and how to distribute the manpower  should be the question.

Don't get me started on the Teen Titans!!!!

The original seven for me! 

Batman
Wonder Woman
Superman
Flash (Either one)
Green Lantern (Hal Jordon or John Stewart)
Martin Manhunter
Aquaman
 
And I would love to see join the team or at least make a guest appearance or two: Black Canary, Green Arrow, Mr. Miracle, Vixen, Hawkgirl, Oracle, Nightwing and the list goes on and on. I just loved how Justice League Unlimited was. You saw your favorites, even the ones that are not so popular, at least once. Awesome.

I would say Grant Morrison's team was the best to already exist but my dream team would be: Nightwing, Donna Troy, Wally West, Kyle Rayner, Power Girl, Tempest, and Martian Manhunter.

Hmm... Nice Article
 
Superman
Wonder Woman
Batman 
Green Lantern (Rayner)
Captain Marvel
Firestorm
Flash (Wally West) 
 
Reason? Cause they'd kick arse, and be iconic and awesome whilst doing it :P

Superman 
Batman 
Wonder Woman 
Aquaman 
Martian Manhunter 
Zatanna 
Hawkman

Best line up 
Nightwing 
Flash (Wally West. I like that guy.) 
Vixen (When she had the ability to also copy humans powers including Green Lantern's)
Dr. Fate 
ICON 
Green Lantern (John Stewart. Nearly recreated an entire solar system. His will exceeds the power of the ring. MY kind of guy.) 
Blue Beetle (Jamie) 

Got to admit that i'm more of a Marvel Comics man but if i was to pick a Justice League team then i would have -
 
Superman
Batman
Wonder Woman
Hawkman
Captain Marvel
Grreen Lantern
Black Adam

I'd basically want a mix-up of the current line-up and the JLI, so something like this:
Batman
Wonder Woman 
Black Canary 
John Stewart 
Big Barda
Mr. Miracle  
Atom (Ryan Choi)
 
It hurts not including Martian Manhunter or Vixen, but since I can only choose 7 they'll have to settle for frequent guest appearances.  Either way, the team has everything it needs - leadership (Batman and Diana), brains (Ryan, Bats, and Mr. Miracle), tactics (Canary, Batman, and Mr. Miracle), muscle (Diana and Barda), cosmic connections (John), diversity, and hefty doses of awesome. 

Granted, I'm probably the only person on the planet with this "dream team," but hey, it's not my fault people have bad taste.

sticking with the 7 rule I pick 
Batman 
Superman 
Wonder Woman 
Barry Allen 
Hal Jordan
Green Arrow 
Black Canary.
And for JLI (with a 10 rule because it's international):
Nightwing 
Captain Marvel
Power Girl 
Wally West 
Guy Gardner 
John Stewart 
Aquaman 
Red Arrow/Arsenal
Cyborg 
Captain Atom

The original seven is probably the best, but I'd like to see the following

Wonder Woman
Flash - Wally West (since the Flash series is about Barry Allen, Wally could be hanging out with the Justice  League instead for all the Wally fans)
Captain Marvel (we don't see him enough, he's a defender of earth)
Martian Manhunter

The remaining three spots can be filled out from the following, not sure who I would pick.... I do think we need Batman or Nightwing for intelligence on the enemy though.

Hawkgirl
Green Lantern, either Jon or Kyle  -- again, a good chance to give the spotlight to someone else  
Superman
Batman (or Nightwing)
Aquaman

Of course, I would be all about replacing Batman with Nightwing, Superman with Supergirl, and so forth.  Batman has to be pretty exhausted ;)

I like the animated JL roster: 

• Martian Manhunter 
• Green Lantern (John Stewart) 
• Wonder Woman  
• Superman 
• Batman 
• Flash (Wally West) 
• Hawkgirl