Seriosuly now, as a suggestion of method, why don't you choose the hotest actor at present, or the lead actor from a widely held, upcoming blockbuster. Maybe from Xmas, or Summer seasons? You could also consider who you think amazed everyone with the best acting skills in the recent past. Someone that wowed the crowd.
So, without giving names, there are three different ways you could choose a poster. Good luck and congratulations on your near future delist.