I only want Bale as Batman. And also, I want Ryan Reynolds back as the Green Lantern! And of course Cavil for Superman. I enjoy continuity, and I feel RR did a fine job with the part, and any short coming from his film wasn't his fault.
That said, yeah so I have this idea in my mind of how I would like to see the JL movie start.
I'd like to see it start right at the end of The Dark Knight Rises film. Replaying the last 3 or 4 minutes, give or take.
So it opens with the finale of TDKR when Batman's ship blows up.
Than the camera moves in, and after all that debris and dust has settled and fallen into the ocean, from that huge bomb Bane was going to use to destroy Gotham City with, we see Ryan Reynolds there, flying in the air, in his GL suit with his hand extended and a green beam being emitted from his ring, and at the end of the beam, is Bale's Batman, encased in a circular ball shield where he was once sitting in his ship, saved by The Green Lantern. Hal than takes Batman from Gotham to tell him of the Earth's impending danger.
Anyway, so with the rest of the cast:
A good Wonder Woman could be played by: Charlize Theron. Bar none, hands down she would do the part great justice.
A good Flash could be played by: Jake Gyllenhaal.