If you are looking for a non-RRSP trading alternative, look at Tuco Trading. They're a US based firm offering SIPC insured retail accounts and prop (licensed or non-licensed). Opening an account with a Canadian address is not a problem.
IB is the clear alternative if you want to trade more than just stocks, or want to trade foreign equity markets. Tuco's retail rate though is .35 per share and has much much better software and customer support.
I have traded with this group for several years, you can PM me for more info.