First of all - i would like to say that anyone who rated this movie bad or low -has not seen it otherwise there is no way not to appreciate this film. Karan Johar, Kajol and SRK make this movie work.
Karan Johar - simply he has done pure justice to his audience - with his best work yet without a doubt. He has finally come out of his little slump. Kajol - her acting of the highly energetic eccentric role of Mandira was just perfect- most likely she will bag the best actor for the awards of 2010. Now finally to SRK who people are comparing to the role done in Rain Man - that was hollywood and noone can copy good acting - only good actors can do good acting - if that makes any sense. He is sure to win the best actor award for 2010 (i know its quite early) but im pretty sure unless Hrithik bags it for Guzaarish because i think that movie we will get to see a completely different HR thanks to Sanjay Leela Bhansali.
On a personal note - i thought this movie was perfect and will not spoil it for anyone - but i do have to add that this movie is not so much for the indian audience as it is for the muslim and international audience. That may sound biased but believe me this is the indirect truth.
I wish all the best to My name is khan and hope it gets the same success as 3 idiots and inshallah much much more - beautiful movie.