Of course, finding "good" items is based on luck. It may be trying to drop sets or uniques that don't exist... To truly tell, you really need to look in-depth at the items dropped.

Just for those unaware, if the game attempts to drop a unique that does not exist, it will drop a rare of that item type with 3x the normal amount of Durability.
If it tries to drop a set item that does not exist, it will instead drop a magical item of that type with 2x the normal amount of Durability.

Mainly, finding good items is a bit based on character level, a bit on Magic Find %, and a LOT on luck...