in my running services, i only have these running all the time:
GTalkService (optional)
SnsService
Swype
DMService
OmaDrmConfigService
From what i noticed, those are the bare minimum.
when i first got the phone, i was only getting about 10 hours of battery life and i was hardly using it. i tried task killers but only found that i didnt know what i was killing and it caused my phone to freeze/lag a few times. uninstalled them and just closed anything i wasnt using manually and i started to do fine. cycling your battery a few times (run it out and charge it up).
it really depends on how you use your phone. if youre constantly browsing and interacting with the screen, your battery will easily be dropping 10%/hour.
if your phone is inactive, then just make sure youre not running updates/syncing more than you need or have your wifi, gps, bluetooth on when youre not using it.