Hello Jeet I have this camera and I love it. I have not used it for video but for still images I think it is fantastic I have been pleased with the results I have been getting from it, I am very new to photography and I bought it due to the price to see if I enjoyed the hobby (I love it) but I will be keeping my D3100 for a while yet. Take a look at some of my images on this forum all taken with the D3100 hope this helps. I have heard that the canon 550 is the better one for video, but if you want a video camera buy a video camera.
All the best
Spen.