I am a canon man, thru i not going to deny nikon makes a good cameras and lenses, i personally shoot canon, but both of my photography jobs i used there nikons, they are equally good brands in the own rights, the biggest thing that you will notice between canon and nikon are they way the pictures come off the camera. people say "nikon is artsy and canon is natural(how you actually see it)." after shooting both thats not necessarily true. its all in post processing in digital photography, the one thing that separates the two is the way they process the images on camera before you export them to computer. Canon images require less post-processing then nikon, they are better images straight off the camera. Nikon, even shooting in raw need post-processing more than canons do, but if your handy with photoshop to correct images this is an not a deciding factor.
Really is comes down to preference, what have you shot, what do you feel more comfortable with. its a big investment, and there's no need to rush, I like the way canon places their buttons on the camera, better ergonomics, and the user interface blows nikon out of the water IMO, on canon everything is just there. On a Nikon I feel like I have to search for something that should be right there in front me.
The one thing Nikon has always done that canon hasn't is lens compatibility, you can use a film lens on a modern nikon and it will still work, Canon lenses are more specialized which is good in its own way but lessens lens choices (without getting mount adapters).
Hopefully this helps lol
I would recommend a
Nikon D7000 or a
Canon EOS 60D, those are both equally good cameras and won't be outdated for quite some time.