Dude nobody can give you one answer for this, every CM rom has its merits and demerits, you will just have to read the user reviews of all the roms and decide which features are important for you and which you can live without.

For stability you can try the latest nightly and the FAT version. They are both very good. But if you want battery, stick with stock.
For themes lookout for teamcooper and adreno ace roms, they are pretty heavy on themes.

 

+1 for this

 

groan.....groundhog day........!! :sleep: Root, screw your ACE & accept half the functions won't work anymore!! Doh! :ahhhhh:Graham. (never has my signature been truer!) LOL!

 

The Cyanogen nightly cooper is very good and Sunday revenge is a very quick lightweight ROM. They both work fine with all the functions doing what they should do.

With that attitude Graham we wouldn't have had smartphones in the first place, dont be such a luddite, people use custom ROMs because stock can be very basic and at times shoddily put together. Huge corporations don't have the best reputation for customer services.