So, I've had great success with two extended batteries that I tried off of ebay. Here are the links, one is a fat and one is the same size as the stock battery.
2300Mah Battery: This one is seeming to do very well for battery life. It gets about 1.5x the original battery and seems to last me all day if not two days with a few hours of gaming and data always on. Straight gaming it seems to be anywhere from 7-8 hours, it kind of fluctuates for some reason, but it's really not a bother.
3600mah: This one is also excellent, especially for those long periods of gaming you want to do. It will last AT LEAST 10 hours if you're having a gaming session with data on, and about a couple hours more with it off. If you're only lightly using the phone (phone calls here and there, texting, light gaming, light web browsing) it will last for about 3 full days. Great battery choice for those who want a lot of juice.
Hopefully this helps some people out! Let me know if you guys have any other questions.