It depends where you are. Colba ADSL2+, if you are close to CO's is the best deal when you get 15mb+. Check the coverage map here: »
colba.net/map2plus.php?lang=frLowest cost is Teksavvy cable basic 5/1mbps with 300gb for 24.95$/month.
Then go on with Acanac (Distributel) 10.5/1.5 mbps cable unlimited for 39.95$ if paid yearly.
Last is Acanac cable 30/3mbps unlimited for 56.95$/month if paid yearly.
If you need more bandwith, CIK Telecom offers 60/4mbps cable unlimited for 99.99$/month.
If you are in an area where Bell offers FTTH service, might wanna check their Fibe 50/50 symmetrical service now that you can have it with unlimited bandwith.