I like Aquaman, and I think a show featuring him would certainly work. I could see an Atlantian drama with powers mixed in doing very well and fitting in with the DC world that the CW is creating. I'm also looking forward to seeing how Jason Momoa does in the Aquaman role for the upcoming Batman vs Superman / Justice League movie(s).
Green Lantern would rock as a TV show and he certainly deserves a reboot after the 2011 movie flopped. Hal Jordan has such a great story and it all seemed to be glazed over in the last flick. Poor Ryan Reynolds is always being handed super-hero roles where the story either contradicts with what the character stands for, or has a crappy plot and he always takes the flack for it. I think the CW would be the only network able to pull off a Green Lantern show, because it would be so special effects heavy and they have proven they can do effects with superheroes well with The Flash.
I hope they do a villain show like the Suicide Squad. Arrow has already featured the Squad, and the actors are pretty cool. I also think the dynamic of making bad guys be good guys is pretty cool. Lastly, The Squad is constantly losing and gaining members in the comics. It would make for a fun, although morbid, way to showcase different baddies and their powers.