I'd like to put a picture of the hero as well next to everyone, but that would mean only 5 people per post unless I made some kind of picture putting them together, but I'm not quite sure how that is done tbh... if someone tells/shows me maybe I'll edit the posts later on! I was toying with some kind of Young Justice original live action series thing in my head, and for a long long while now I've been just casting people for, as lame as it sounds, fun. Lol So, I figure it's time to share some of my ideas.
I know some of these people are probably going to be shot down, and I'm cool with that, just shows what you guys think on them. They are all supposed to be in high school, the cast is mainly 20 something year olds, I tried not to make them too old though, usually 25 or so was the oldest, sense Tom Welling was 24 when he began playing Clark, right?  Let's start with the heroes:
Kevin Zeggers as Nightwing
I like to tend to leave it to acting ability mostly, but Zeggers looks like he could play a good Nightwing. That's not to say he's a bad actor though, because he's actually got the acting to back it up! He's an excellent actor, it just feels like he doesn't have a specific role to define him, just check out Frozen. 
Ryan Kelley as Robin - Tim Drake
I loved him when he was younger on Smallville, which as some of you on this forum know I only started to watch a few months ago, so his role was pretty fresh in my mind. I went to see what he had been up to and saw that he done a Ben 10 live action movie, liking the Ben 10 concept anyways I watched a bit of it. He seemed pretty secure in a hero like role, so I figure he's got a good frame and such for Robin, it could work.
Robbie Amell as Superboy 
I'll be honest, the kid just looks like a fit for Superboy. Nobody else seemed to fit... I'd be open to suggestions on this one. Lol
Ashley Benson as Wonder Girl - Cassie Sandsmark
A cute young blonde, she fits. I like Ashley though, she's a fantastic actress whom I've enjoyed sense her small role on Supernatural. 
Max thieriot as Beast Boy
He's got a slender build, and if you've seen My Soul To Take you see that he can play odd, and an outcast, that's pretty much how I imagine Beast Boy, simply based on the Titans cartoon from a few years back though. 
Jean-Luc Bilodeau as Impulse
He just seems to fit to me, what else can I say? He's slim like Bart... he was great in Trick r Treat, but needs a bigger role, why not this? 
Shanae Grimes as Aquagirl
Great young actress, she always has been. She's quirky and fun, and judging by her role on 90210 she likes water, right? Lol 
Raymond Ablack as Green Lantern - Kyle Rayner
Sure, he's not even white, but hey, that diversity isn't it? Lol, but really Ablack shined on Degrassi (whatever, it's a good show lol) and deserves to be known more! He's also got a good look for Kyle IMO, the hair and all kinda works. 
Mary Elizabeth Winstead as Barbara Gordon
For some reason she seems perfect in this role to me! Sure, Barbara has red hair and she doesn't, but Barbara has always been that really cute girl, and that's Mary! She also just needs to be involved in this because I love her... 
Emily Browning as Raven
Browning always just got the kinda of depressed or something look that totally works for Raven! She's also a phenomenal actress that I've taken a shine too!