There is no "best ROM". A big part, especially for battery, is dependent on what apps you use. Your only solution is to try them.
That, and given the open swearing, i am just closing this here. Lets not repeat this...
HTC Blue Angel (retired)
HTC x7501 (retired)
HTC Incredible, w/ AOKP (GPS use)
HTC Rezound (backup phone)
Samsung Galaxy S4 w/ Dirty Unicorns
B&N Nook Color, w/ CM10
HP Touchpad w/ CM10
Google Nexus 7 w/ Stock Rom (STOLEN....
If you have any problems or questions, do not hesitate to ask. I don't bite!