A nice person from the YMCA dropped this link by in an old thread about getting gym passes for free. Until June 30, 2011 you can redeem this pass for a free 2 weeks at your local participating YMCA if you live in Ontario.
My favourite gym is at my local YMCA. Their prices are reasonable, and they have courts, gyms, an indoor track, a pool and everything else you expect from a fitness centre.. and more. The pool is the biggest drawing point for me, I love to swim. I really wish that pass was for the rest of Canada as well.. I could get in a lot of swimming in 2 weeks! :-)