Considering the pics you've chosen (Srk pic is not visible I don't know why but if my guess is right you might've shared Srk from Don 2)
Srk in Don 2 > Salman Khan in Ek Tha Tiger > Hrithik Roshan in Bang Bang > Aamir in Dhoom 3
If you had shared Hrithik from Kaho Naa Pyaar Hai or even Dhoom 2 then Hrithik would be ahead of Srk by a distance but for me Hrithik would always look good in a car.
But if you take off screen then Salman Khan wins by a distance. Bikes in real life belong to Salman Khan. And also if you had shared any other pic of Salman Khan on bike apart from the one from Jai Ho then he could even go past Srk, considering on screen ones.