The three standard recommendations around here are (in alphabetical order): Fidelity, Schwab, Vanguard.
My kids all have Schwab Roths and I have been pleased with Schwab's service. I've also had other accounts and Fidelity and Vanguard and have been pleased with them as well.
People will discuss the differences and pros and cons of the three, but I think all three are good.
I've never had an account with TDA, but as a volunteer tax preparer I've seen people bring in their TDA tax statements a number of times. For those TDA customers who have an advisor, their accounts seem to be sliced, diced, and churned, and they're definitely paying more in taxes than they need to, which is less money that they'll have later.