I personally think it would be.. Bipasha but unfortunately they made her role very comic She had really worked hard on her body and she is a decent actress too.She looks strong.felt everything was so biased.she is also not as famous as aish but she is very well suited for a dhoom girl.Absolute cat-woman Was esha good?she was quite nice.had a nice bod,good dancer. katrina..great bod,nice looks,but looks expressionless. Aishwarya,is more suited for sanjay leela bhansali films.she is more of the delicate types.Honestly,never understood the hype about her body in dhoom 2.she had def lost weight but she does not have "THE BODY" and strength to play a dhoom girl.she also does not look that good as she looked in her other movies.looked very fragile and annoying when she tried to ACT COOL. who do u think rocked as dhoom girl?
I too think aishwarya was over hyped but katrina was good.she worked very hard and u can see that on screen.problem is her beauty was more concentrated. esha was fine.noone expected dhoom to be major hit.hence they cast esha lol. but as u said,i thin bipasha did not get her due.
Bipasha was great in double role..... I liked Ash too ....Esha was ok . Katrina did ok with what little role she had.