The Flash:
Classic
Jay Garrick

Superman:
Classic
First Appearance
Man of Steel

Batman:
Classic
First Appearance
1970's
1966 TV Show
Original Intended Design or The Bat-Man. Yes I'm serious.
Batman Beyond
The Dark Knight/Rises

I'll expand upon it later.

EDIT

Aquaman:
Classic

Green Lantern:
Classic
Movie Suit
Alan Scott

Catwoman:
Classic
First Appearance
Modern
Batman Returns
The Dark Knight Rises
Halle Berry

Bane:
Classic
Batman and Robin
The Dark Knight Rises

Harley Quinn:
Classic
Arkham Asylum
Arkham City
Harley Quinn's Revenge

Nightwing:
Classic
First Appearance
New 52

Green Arrow:
Classic
First Appearance
New 52
"Arrow" TV Show

Sinestro:
Classic
First Apperance
Movie Suit

Metallo:
Golden Age or "Metalo"
Classic
Modern

Since every costume so far has been a "reimagening" of sorts, I see everyones Alt being more in line with there comic book apearances.

Characters like Batman and Supes will probably get more though.

Batman, new 52,batman begins,dark knight. Green lantern,hal jordan,alan scott. Catwoman,long halloween,batman returns.

I just want to see a classic Harley Quinn costume. I'm not to crazy about her new look :/

Superman=Superboy
Wonder Woman= Wondergirl
Flash=Kid Flash
Aquaman=AquaLad
Green Arrow= Red Arrow
Nightwing=Robin=Arkham City

Slim Chances but still would be cool

I suspect that you watch young justice? That actually is a neat idea though.

Batman - Batman Kingdom Come - Batman Beyond - Classic

Superman - Man of Steel - Classic - 1940's

Wonder Woman - Classic - New 52 - 1970's

Green Lantern - John Stewart - Alan Scott - Green Lantern Movie

Flash - Jay Garrick - Wally West - Classic

Harley Quinn - B:TAS - New 52

Solomon Grundy - Victorian Attire - "Tornado's Path" Suit

Lex Luthor - Brainiac Suit - Classic

Aquaman - 1990's - Classic

Green Arrow - New 52 - Classic

Joker - Classic - Heath Ledger Style

Hawkman - Golden Age - 1970's

Captain Marvel - Classic - New 52

Black Adam - Royal Attire - Whiz Comics

I may be the minority here, but I'd like to see more original NRS interpretations rather than retreads of old designs. Barring that, a mix maybe? More originals with some throwbacks in the mix. All unlockable rather than Nicole and dime dlc.

While I can agree with that, isn't NRS doing just that with the primary costumes, though?

Basically what I was going to say.

Batman-
1989 Batman movie
Batman Begins
Dark knight Rises
Classic Blue and Gray

Superman-
Classic
Long hair

Joker-
Dark Knight Movie

Catwoman-
Batman Returns

Flash-
Classic!

All of the costumes in the third act of Justice.

Yeah those are good choices(super man with long hair>???).But the dark knight thing is unlikely.Actually if you go on google you can search "Injustice gods among us joker leak) and it shows a pic of joker on a computer in the background of a fight.But even if they don't go with that look then i'd have to say the killing joke? maybe something like the arkham games? Fun-Fact Netherrealm actually helped in the development in arkham city.Not sure how much but they're in the credits,maybe it's because they made arkham city lockdown?