If you’re with a broker, who charges double digit transaction fees – leave them. I recommend Interactive Brokers.
Don’t take my word for it, check out slide 13, from the deck IB put together in November [pdf].
I also want to point out, regardless of your broker, the average trader actually beat the S&P…Even folks using Ameritrade 
UPDATE: The last statement, was more to poke fun at Ameritrade clients, than anything else. I was not clear, and should have said “according to slide 13″, and thanks to Mark, for mentioning that this data does not accurately point out deposits (or, withdrawls…for that matter). Maybe everybody was moving money from their Schwab account, to IB…hahaha.