Those are really the only three to speak of, since all other Canadian Wireless companies are either owned by one of those three or use their networks (ie Fido, Solo etc).
Rogers, Bell, Telus, Virgin Mobile, Solo (Bell), Fido (Rogers), Koodo Mobile (TELUS), MTS Allstream (Manitoba), SaskTel (Saskatchewan)
There are also a host of other small scale providers such as Presidents Choice Mobile (PC Mobile), etc. most of which are either linked to Virgin Mobile or one of the other major cell phone providers.