Can anyone suggest a good stock trading site?

I use Schwab the most. I like the feel of the Streetsmart Pro software. They are not the cheapest however. Fidelity can be cheaper, Scottrade even cheaper and TradeKing seems to be the winner in cheap @$4.95 ..

However if you are not a trading madman, the price difference is not significant. If you keep large free cash balances, then the cheaper guys will get you on the interest side of the equation and pay less on your cash. Schwab has the Value Advantage Fund which pays about 4.20% right now.