I disagree with noelm. In fact, you don't get what you pay for, therefore, you should pay nothing.
There are several brokers where you don't have to pay anything if you purchase the most popular products. Fortunately, those products are the ones you should be purchasing and those products are low-expense-ratio, passively-managed index ETFs and/or index mutual funds.
The SmartMoney review has several mistakes in it, so take it with a shaker of salt.
Brokers with free trades on ETFs and mutual funds and stocks:
WellsTrade, but the minimum account size for free everything is probably too high for you. No charge for any ETF or index fund whether Vanguard, iShares, Fidelity, Schwab, etc. Best linkage to checking account, too. Best multi-account screen display. Best notification of dividend payouts. Best 1099 tax reporting.
Brokers with free trades on ETFs and mutual funds but not stocks:
Fidelty, but selected free-trade ETFs are limited to a few iShare ETFs. No charge for Fidelity Spartan funds. You pay a commission for stock trades, but you shouldn't be buying any individual stock shares anyways.
Vanguard, but selected free-trade ETFs are limited to Vanguard products. No charge for Vanguard funds. You pay a commission for stock trades, but you shouldn't be buying any individual stock shares anyways.
Schwab, also limited selection. No charge for Schwab ETFs and Schwab index funds. You pay a commission for stock trades, but you shouldn't be buying any individual stock shares anyways.
Brokers with free trades on ETFs:
TDAmeritrade, better free-trade ETF selection than Fidelity since iShares and Vanguard ETFs are available. Charge for Vanguard mutual funds. You pay a commission for stock trades, but you shouldn't be buying any individual stock shares anyways.
Others
Sure there are other brokers, but why would you want to pay money for them?
Also there is no reason to pay for any research as all research is free on the internet. Also time to execute a trade is not a criteria for choosing a broker.
Lowest to open an account: Fidelity, TDAmeritrade, and Schwab.
Best tax reporting: WellsTrade, though in 2012 the laws have changed, so maybe all brokers are good.
Best ETF/stock dividend handling: WellsTrade, TDAmeritrade, Fidelity. Worst: Vanguard.
Full disclosure: I have accounts at WellsTrade, TDAmeritrade, Vanguard, and Fidelity.