This is a no brainer by a long mile. SRK it is. People in the north might be tempted to point at Rajinikant, but given a role, Ranji can act really well, and that's how he started out before getting trapped in his image. But SRK, with his much repeated mannerisms, his dependency on an entertaining script to deliver a hit etc, make his the obvious choice. Do you ever remember SRK giving a power packed performance, like AB in many of his earlier movies, where he was just magnetic, and often made mediocre films watchable ? No way SRK can do that. Kamal Hassan should not be even in the options, as he, along with Mohanlal, Naseeruddin Shah and a few others, just need an extremely gifted and intelligent director to be at their best. So, in a way, they are trapped too - but there is no dearth of sheer talent in this case. With SRK, it is !!!