Confused which DSLR to buy?

Could someone suggest me which DSLR would be better. I have no prior expereince with DSLR cameras n now confused between canon Rebel 1100d, 550d, 60d and nikon 3100, 3200, d5100 and sony alpha a37 etc etc… I ahve gone through the descriptions and product specs and understood that there's difference in Pixels, video recording etc etc.could some one suggest me which one to take. I'm planning for nikon d5100 will that be a good choice?

Narrow you choices only to nikon and canon
i use nikon d7000 because everybody knows that nikon has sharper lenses and low noise performance. It's just a matter of how you see the brand itself (eg.mercedes or bmw), see which one fits best in you hand

You should actually start with a Nikon D90 used.