which is better?
obviously 55 is brighter.
why does everyone always go with 35 not 55?
kinda noob question but yea.

 

55w will be brighter but also reduces the life of the bulb.
IMO, the difference between 35w and 55w isn't that big so save your money.
In most cases 55w will just increase glare in a non-HID housing instead of putting more light on the road.