[Q]What is the best stock rom ?

I want to ask you, what is the best stock rom that you have used so far, from wich country or region.

I currently use South East Europe - COC2 and my operator is Orange Romania.

i want to change my current firmware because i have battery drain when using the phone and i don't know what to choose.

Can you please answer with the name of the rom that you are using and the current operator

Thank you