ALERT : If you haven't seen the movie yet [yes, you suck for that], please go watch it. No point in reading this post unless you have not seen the movie.
I was bit late seeing the movie Inception [watched it after 3 weeks of its release]. Whole internet was flooded with appreciation for the movie, everyone telling it's fabulous. Most of my friends watched it and updated their Facebook status with "Awesome" "Mind Blowing" etc. [hell, one friend even updated saying it's hilarious :@]
Most of the people find it mind blowing because of the climax. According to them, the director, Christopher Nolan, clearly plays with our mind and keeps the ending to our guesses. But no from me, I got the movie :P.
As you have seen, at the end totem keeps rotating, making ambiguous assumptions, whether it's reality or he is still in limbo. Many explain that, in whole movie, Cobb, the protagonist, was in dream. But it's wrong people. When I saw the movie, I was like 'Meh', because it didn't blow my mind away. Yeah, it's a pretty good movie, I rate it 8.5/10, but not 10/10 as many do. And to be honest, people who didn't understood the movie gave it 10 :P
So, lets get to point, according to me, in climax, it was Real. COBB WASN'T DREAMING NOR HE WAS IN LIMBO.
Proof I :
I came to above conclusion for the first time itself when I saw the movie. At the end, if you observe closely, the rotating totem loses it's momentum. It never should happen in dream. So it makes clear that, he wasn't dreaming. The totem loses it's momentum and eventually falls off, which is not shown by clever Christopher ;)
Also, in credits, if you see, there are two sets of Cobb's kids at different ages. Though, one can argue that they were growing in Cobb's dream. But I was really impressed by Director for this.
Proof II :
Many of my friends didn't agree with me for the totem-momentum thing. So here's the clear proof that, Cobb wasn't in dream. The shoes worn by kids in Cobb's dream are different those are of in reality :D
Following is the sceenshot, took at 58 min of movie.
Now, this screenshot is took at the end of movie, 2.20 min.
See the shoes color, it explains everything that his dream and reality are entirely different :D