TradeStation
TradeStation is generally focused on active and experienced traders so if you have been trading for a while, they might be the right broker for you. Recently they have been trying to appeal to active traders and are now offering $0 trades. This broker has plenty of data and tools to help you out and all of their trading platforms are high quality.
They have no account minimum but the thing is, in order to use TS Select, you need a $2,000 minimum account balance. In order to trade for free on their more advanced platforms, TS Select is required so really you can't use the best with an account that has less than $2,000 on it. TS also has a lot of fees that users have to pay. They have annual account fees, inactivity fees, $125 outgoing account transfer fee and more.