Superman - Hufflepuff (but I'd conceivable argue for Gryffindor but he is
called the Big Blue Boy Scout)
Wonder Woman - Gryffindor
Green Lantern - Ravenclaw
Martian Manhunter - Ravenclaw (hands down)
Aquaman - Gryffindor (though he sometimes fits the Slytherin profile)
Flash (Barry Allen) - Hufflepuff (conceivably Ravenclaw)
Flash (Wally West) - Gryffindor
Green Arrow - Gryffindor (not even up for debate)
Batman - Slytherin (I'm sorry, I cannot see him ANYWHERE else)
Black Canary - Gryffindor
Plastic Man - Slytherin (I might hedge on Gryffindor)
Blue Beetle - Ravenclaw (where else for a technical genius?)
Booster Gold - Gryffindor (not much in the hard work department for Hufflepuff,
is he? LOL!)
Captain Marvel - Hufflepuff (SHAZAM! BADGERS!)
Supergirl - Gryffindor
Nightwing - Gryffindor (like he'd go anywhere else!!!)
Robin (Tim Drake) - Ravenclaw (though he's kinda like Hermione...smart yet brave)
Catwoman - Slytherin (like she'd go elsewhere, though she's a hard working cat
burglar...LOL!)
Donna Troy (Wonder Girl #1) - Gryffindor (like her and Wonder Woman fit anywhere
else)
Aqualad (now Tempest) - Hufflepuff
Changeling - Gryffindor
Cyborg - Gryffindor
Starfire - Gryffindor
Arsenal (former Speedy) - Gryffindor (this was difficult, I could see him snagging
a Slytherin call too)
Batgirl (Barbara Gordon) - Gryffindor (like this was up for debate?)
Batgirl (Cassandra Caine) - Gryffindor (but could she snag a Slytherin?)
I realize a lot of non-comic book readers might not recognize some of the newer characters, so I can only direct you to http://www.dccomics.com There they have origins of most of these characters. Otherwise, there are like a ton of sites out there, all you have to do is type in a search in Google or Yahoo to find them. (grin)