Here is my Fan Cast list for a Aquaman movie.
Dustin Clare - Aquaman
With so many former "Spartacus" joining the DC universe in "Arrow", I thought why not to take the fan favorite actor (and character) from that show and put him as Aquaman.
He has the charm and the charisma. If he goes blond, grows a small blond beard and gets back to gladiator shape, he can be perfect for the job, as the king of Atlantis. We know he can do the action and the fighting, he has the look and the body, and he is a really good actor. And he isn't really an unknown, and he is only 32.
Another thing, since Aquaman's origin story has changed over the years, I think that in the movie he should be half human and half Atlantien.
Gemma Arterton - Mera
originally I wanted Gemma to be Wonder Woman, but since that's not going to happen, she can be Mera. She wiil need to dye their hair to red, but Scarlett Johansson did the same to be Black Widow.
Gemma is a great and beautiful actress, and she can be perfect as Mera.
Wes Bentley - Ocean Master/Orm Marius
Ocean Master is Aquaman's half brother and he needs to look like him but in the same time be very different. And Wes is the guy for the job.
Kevin McKidd - Thomas Curry
Few years back, Kevin McKidd could have been a great Aquaman, but that ship has sailed. Know he can be his daddy.
Rachel Nichols - Atlanna
Some will say that Rachel should be Mera, but I think Rachel should play Aquaman's mom. She dies after she gives birth to him, so she needs to be young.
Stanley Tucci - Vulko
Unless somehow Tucci will be Lex Luthor (unfortunately that won't happen). Just from looking on the picture above, I think Tucci needs to be Vulko, the mentor of Aquaman.
If you want, you can watch a fan-made trailer that I did for Aquaman movie a while back: