TD Direct Investing is a solid, easy choice choice for implementing a couch potato/mustachian investing plan. I use them personally but have no affiliation.
They charge 9.95 (or 9.99???) per trade. This is pretty standard in Canada among discount brokerages offered by the big banks. The reason my SO and I went with TD Direct Investing, however, was their e-Series index mutual funds. Here in Canada, we don't have access to Vanguard mutual funds, and when I was setting up my account about a year ago, TD's e-series funds had the lowest MER's (fees) and a reasonably wide selection (Canada, US, international, bond, etc.). You can only purchase the e-series funds from a TD direct investing account.
I had a somewhat complicated account setup process. My SO and I are both US citizens (Canadian permanent residents), we have investments in both USD and CAD, and I wanted to have trading authorization for all accounts, including my SO's registered accounts that can only be in his name. Despite this complexity, the accounts were set up without too many complications. A lot of the setup is done over the phone (24 hour), and I actually found that to work very well. Limited/no wait times, and the people who picked up the phone actually knew what they were talking about.
It was relatively straightforward to setup automated money transfers from my chequing account to my unregistered and registered investment accounts. It was also straightforward to set up automatic investments.
Other fees I am aware of: If you don't have $25k in your RRSP, you'll theoretically be charge an annual $100 fee. I don't have close to $25k in my RRSP (haven't earned the contribution room in Canada yet...most of my earnings were in the US). However, I've had success two years in a row now having this fee waived with a simple phone call. This may have worked because the overall balance in my non-RRSP accounts is relatively high, or it may be easy for anyone to get the fee waived.
If you are looking to trade more actively and use ETFs instead of mutual funds, going with a lower cost brokerage like Questrade or Interactive Brokers may make sense. But then you'll lose out on the lower MER mutual funds.
