Armor sets (DKS) - or see Lancet's DKS FAQ/Guide

I used the full mining guild set for awhile (level 16 to 28), which is one of 3 sets you start with in the Steam version or North American Xbox version. Other than that, I never used more than one piece of any set, though I did equip several full sets to check them out.

I have not played the Witcher 2 (waiting until I build a new computer), but there is at least one topic about it in the RPG Chat forum.