The best battery life I ever got was from Gingeritis 3D VI with Ziggy's kernel and chingy's battery saving suggestions. However, I grew tired of Sense and am now running TheROM V4 with everything stock EXCEPT I went crazy and installed the CDMA v1.39.00.0430 from the 2.01.605.0 RUU since I kept noticing that Cell Standby was taking up 75% of my battery life. Since then I've been getting a good bit more use out of my phone.
TL;DR - TheROM v4 / Stock kernel / CDMA v1.39.00.0430 / LTE v0.01.78.0802
TL;DR - TheROM v4 / Stock kernel / CDMA v1.39.00.0430 / LTE v0.01.78.0802