As you know there will be a Justice League movie coming out in 2017 and with the cast confirmed including the Green Lantern yes including Hal Jordan's Green Lantern, he will be played by Dan Amboyer an actor who will be appearing in Batman vs Superman Dawn of Justice as a drone pilot.
As you can see not all of the Justice League has been cast but only one that's left, Martian Manhunter, it wouldn't be the Justice League without our favourite psychic,telekinesis,shape shifting martian, Martian Manhunter. For him I have 5 actors in mind for Martian Manhunter (well technically John Jones).
Idris Elba said it himself he didn't want to play Heimdall for Thor anymore so what better way to let him play a superhero than giving him the chance to play Martian Manhunter I mean he's a great actor he did a great job with Heimdall I'm pretty sure he'll make a perfect John Jones/Martian Manhunter.
I'm sure most of us know who Jimmy Jean-Louis is and as you know Martian Manhunter/John Jones is a man of few words he is a man of wisdom he likes to give people hope Jimmy Jean-Louis is that person like how he did it in the 2006-2010 TV series 'Heroes' as the hatian he is a man of wisdom and so is John Jones.
Yes I know he's been suggested before, but go watch him in Fringe and try to tell me he wouldn't be perfect as Martian Manhunter and besides a lot of photos online showed him as Martian Manhunter I mean come on he's a great actor and he would be the perfect Martian Manhunter (besides Jimmy Jean-Louis).
Sure Denzel Washington might be old but look at what he did in The Equalizer sure some might say it's a bad movie and some might say it's a good movie but he did good in that movie just it wasn't all too great with the movie he can look fearless he can be a murderer like in The Equalizer and that's why he's on this list so he's old so what.
Dwayne 'The Rock' Johnson
I know both of them are taken but come on you got to hand it to them the art is pretty impressive