Nikon d3100 or Canon T1i?

It's good you're asking questions, but you're asking the wrong question. The camera body is NOT more important than the lens, you've got it backwards. Once you've bought into a camera system you're stuck with it as lenses aren't interchangeable between brands. You probably can buy a grey import camera in Canada for similar money if you shop around. I'd buy a 3 year warranty on top of it. I'm not familiar with both of those cameras, so I don't know what features are missing, but both brands are good and you can always purchase better lenses down the track.