It would certainly help people around here to know a little bit more about what you're trying to shoot...
You can still use websites to compare their specs : http://www.dxomark.com/Cameras/Compare/Side-by-side/Canon-EOS-1200D-versus-Nikon-D3100___940_664
I would look around me, if I have friends who also shoot and maybe my final choice would be to get the same brand as them, it will be cool to share lenses with them...