Why would you need to jailbreak for free games? There are plenty of free apps available on iTunes or keep an eye on promotional sites like www.freeappaday.com and www.freegameoftheday.com where you can pick up some great paid games made free for a limited time.
Whilst I am sure you are not, but if I have misunderstood you and you are looking for information on piracy and ripping off developers by stealing their paid apps then macrumors does not take kindly to such discussion within their forums.