Supergirl and Poison Ivy seem interesting so far.
I like how Supergirl has various tools to deal with many situations and how you can easily switch between playing offensively and defensively with her, which imo is very Chun-ish. She's pretty effective at any range.
I haven't played enough Poison Ivy, but i'm liking her a lot so far. I really don't mind the level of execution required to play her since I've played execution-heavy characters in other fighting games. Ivy's footsie game is great, her walkspeed is fast like Chun-li's, has some great normals and does seem like a pretty well-rounded character, but it seems like she doesn't have any good wake-up tools. However, I do think Ivy fits my playstyle the most and really resembles the way Chun is played in SF.
I've been watching some tournament and ranked matches of Aquaman, and so far i'm not really digging the way you have to play him. I'm still planning on trying him out though just to see how good his normals are.