Ghajini is superb. According to me Ghajini is Aamir and Aamir is Ghajini. Nice story (I have not seen the Tamil version or memento) , strong acting from Aamir and team. Tinu anand impressive in the cameo. Jia is also good. Asin, I felt there was some tendency of over acting. Some actions and chase have south flavour. Also I realy feel that against Aamir the villains should be little short in height :P
Else the movie is very well researched and presented in an excellent way, especially keeping the note of everything and in proper places.
A good movie to store in your movie library.