I won't go into detail about Crosfit--suffice to say it's very intense and unconventional and effective.
The Crossfit Toronto gym has knowledgeable and helpful staff that will help you get in the best shape of your life. They are open to questions, even criticism.
The only reason I give them four stars is because training there regularly would become too expensive--as it is, most people go there for either independent, occasional sessions or 30-day bootcamps.