Which is better DSLR?

Can anybody tell me. In Canon EOS 550D & Nikon D90 which 1 is the best for using in both indoor & outdoor photography?

You need to compare similar cameras. The Nikon D5100 is closer to the 550D, feature wise

Here is how their sensors compare

http://dxomark.com/...nd3)/Nikon

The new Nikon D7000 is the replacement of the D90 and the similar Canon is the 60D

It will depend more on your skill/experience and the quality/speed of the lens than the camera body itself.

I always tell people I would take a $600 camera with a $1, 500 lens than I would a $2, 500 camera with a $200 kit lens. A "fast" lens will have better optics, more elements, and a better overall build quality… And that performance (especially in low light) comes at a price.

Sad to say neither camera. They will be as good as eachother.

Get away from the kit based approach. It's the lens that matter's most but first you as the photographer govern how the photo is taken.

The camera does not matter. It didn't matter 50 years ago it doesn't matter now.