You've diligently managed your budget, you've built up your savings, and now you're ready to invest. The next step is to open a brokerage account to buy stocks, funds, and other investments. Picking a broker is no small matter, as each broker fits a different type of investor. Here's how TD Ameritrade and OptionsHouse, two well-known discount brokers, compare for buy-and-hold investors. Deciding which brokerage is best for you isn't just about commissions or trading costs, but it is an important consideration for people who trade more frequently.