My newest favorite (as of April 2017) is Wealthsimple, which is where I hold my Roth IRA. They let you invest in socially responsible companies and they manage your first $5,000 free. In addition, if you sign up through someone else’s referral, you each get an additional $10,000 managed free for another year. My link is here: Wealthsimple-Smart Investing.
Update: since Digit is going to start charging $2.99/month for their services starting in July, I’ve decided to stop using them by that time. That may be okay for some people…but I’m cheap enough that that was a deal-breaker for me. =) Just leaving this here for the sake of information.