For stocks I have used Ameritrade and Vanguard for a long time. Started with Ameritrade for personal and corporate account, and then used Vanguard for Roth and traditional IRA accounts (moved over from Ameritrade). My personal preference for a company is Vanguard although both platforms work fine for me (I trade very little, mostly buy and hold - it could be different needs for a day or frequent trader, so that I can not comment).

I never was confident enough to trade commodities on line. Even though like you I had no need for broker advice, I felt like for the limited number of commodity trades I did a year a fat finger mistake could easily have paid for the broker fees. Plus where commodities need to have something done with them periodically (like get out of a position before delivery date) it was nice to have a broker watching my back so I did not forget something important. With stocks if you buy it and forget about it, it might be a good thing.

For those reasons I never used on line commodity trading. But then I never did lots of trading where the fees became significant. In fact I have not done a commodity trade since the Corzine event, though I do keep a hundred bucks in a brokerage account just to keep it open should I change my mind.

John