I've haven't got a tattoo yet but this is the place that did my piercing and they have some good artists on staff for tattoos:
New Tribe:
http://www.newtribe.ca/
I also hear that Passage is good as well:
http://www.passage.ws/index2.html
I would suggest you visit BME's forums and post this question there. Posters there will definately have the skinny on Toronto's tattoo artists.
http://www.bmezine.com/index.html