I'm using Disnat, their online brokerage service, and it does what I expect it to, while being very easy to use with my regular checking account and being a reputable company that has been there since long before I was born and will likely be there long after me.
To me, it's worth the extra couple of dollars in commission over, say, virtual brokers or whatever, especially since I trade so rarely.
Also, I buy individual stocks and not ETFs, so the free trades at Questrade don't really help me.