SHAW cut my network 2 twice when I was using their 20g service. (Avg. 70G/month..I shared with my family though)
I have switeched to SHAW I-EXTREME internet service (5M) last month, 60G limit/Month. It's fast and quite stable. avg. 600kbs
http://www.shaw.ca/Tmplt.asp?pageID=771
plus I think Telus has its limit too, it costs you $200CAD once you pass its limit..