Grus for borrowing me hindi remake :))
Well, I'm always prejudiced when I see any remake. I think it's mainly because I use to see original version first and I automaticly comprare it with the second one. And I use to hate ppl which hasn't their own ideas!
Ghajini is perfect movie for Aamir Khan. Strong hero, touching story, good music... But somehow, I felt that Sanjay's character lose a bit of it's intensity when he played him. Surya maybe done it in a different way, he doesn't care about abs, he just focused on the man which he has to show on screen.
Aamir loves Stanislawski method, I think, and I used to compare him (very often when I spoke to my un-bolly family) to Daniel Day-Lewis (but I think that he's better actor than Khan but it's just my own opinion). Surya has any method? For sure he hasn't any nickname xD And, hey, it's very unusual for such a star like him, which has a huge fan following, not only in TN.
Back to the topic, the 1st difference between picturarising the same character by this two performers is motoins. Yes, Aamir done all moves in slow one, Surya didn't gave a damn and he does everything faster.
Also the way they made romantic and scenes wasn't similar. Aamir has this strange facial expression which used to send a message into my brain 'hey, he's ugly, he has one face, he have no idea how to play it'. Surya? Yay, in every movie I've seen with him his moves, not only in face, was stricly different. I don'e like Asin, I find her same everywhere, but somehow she managed to make some chemistry between her and Sivakumar, she and Aamir didn't made any - for me he looked a bit odd with her - maybe he's too old? I don't know.
Stunts were mostly similar, even this one with tap :P But... Surya knows how to fight, he from SI, right? And Aamir... Somehow, I was bored looking at him.
Well, I could write a book about this remake and now I don't want to bore you ;) Let's cut the actors collide and let's say that Surya was better.
Asin? Same, same, same. Not only in this remake, anywere for me. Really! Even in Dasavatharam.
Jiah Khan was actually much better than Nayantara. I think they pay more attention to her character but it was still crappy. Anyway - good job, girl. I wanted to kill editors when I've seen how much Latoo is cut...
Pradeep done a different job here than in Tamil version. His character lose his twist.
Plot was mostly same. I didn't liked it at all in both versions but... Somehow I was curious how it'll end. Ending! Different. Hindi was too sentimental for me, tamil was intelligent ;) Hindi was more clear, unlike the tamil. Tamil was better.
Music? AR Rahman never lets you down, but Harris Jeyaraj too. I liked only a couple songs in both versions. In tamil it was Oru Maalai and Sutrum Vizhi (I've heard telugu version 1st and I learned most of both by heart xD In Pokiri Bharat sings telugu one!), in hindi - Latoo and Kaise Mujhe (my classmate was "translating" the text into Polish on Monday, final result was hillarious because she didn't know even a bit of hindi xD).
To end, I would say that the tamil was just like tamil movie, just like hindi - hindi.