I used to play a little bit, but that was before I got on a government network So now I can't. I think the max I won was around $500. However, that only supplied future buy-ins, so overall, I pretty much came out even.
I would be careful the government is SLOWLY beginning to crack down on online gambling - which is not mainly poker - it's sports related wagers - what you need to be careful of is companies that will let you deposit money but have very strict policies on getting your money withdrawn - because you can win a million dollars in a poker tournament with www."xyz".com but it doesn't mean they have to pay you - you are breaking the law if you do it inside the U.S. - slowly the government will get to all of them but for now the biggest thing they do is shut down the companies that are intermediaries (ex: paypal) that have allowed transactions from U.S. citizens to offshore gambling companies. Paypal steered clear of that industry but a similar company : neteller got shut down for doing it.
Word of advice - stick to playing poker with adults not computers! Also don't gamble often unless you are a professional b/c the house ALWAYS wins in the end!