For level 2 to trade stocks I use Stockwatch, it costs me around $100 a month and to be honest with you, I don't know how I could trade with out it. It offers market depth, streaming real time porfolio's, intraday charts, best analytics for canadian stocks that i have found.

If by level 2 you mean market depth on a stock, the real time bid and asks on a stock. I find it one of the worse tools available to investors. Big problem with this tool is the market maker can load either side the buys or the asks and make it appear to be something it isn't. Many experienced traders look at level 2 as nothing but noise. It is used by the market makers to make people think what they want them to think. Often level 2 bid and asks are nothing but fluff. The market maker puts in fake bid and asks to try and lure investors into buying or selling the way they want them to.

 Al

http://www.stockwatch.com/