With my ranger I used the Mining Guild set from level 16 to 28 and the Orobas Bracers from 16 to 25 (these sets included in the Steam PC and North American Xbox versions), but other than that stuck to random equipment.
Once I could start using the Bow of Orobas all the other pieces of the Mining Guild set got replaced, as well, with loot I had been collecting (but until then was not good enough to break up the set).
There is a set I saw recommended for rangers early in the game, as well, but I never collected all the pieces in order to try it.
