I started out using TD Waterhouse, and was overall pretty happy until I was unable to log in for the 3rd or 4th time. It was down way to much for my liking.
Then went to Interactive Brokers, attracted by the low, low commissions, but I disliked everything else - especially trying to get somebody on the phone. Didn't like IB at all as far as getting around, interface, reporting etc.
Been using QTrade out of Vancouver for a couple years now, and it has been truly phenomenal. Amazing customer service if you ever need to call, extremely reliable, good execution, and a very easy concise layout that makes sense IMO. Worth checking out. About $20 a trade, and that goes to $7/per if you trade over 30 every 90 days. (But you have to do the 30 trades first

)The Globe and Mail ranked Qtrade the number one online Broker for four years in a row.