I only know about mage ones, but there are currently 2 that will not be replaced simply by ILVL. Bracers give 300% increased damage on a hardcasted Pyroblast and the ring that allows mages to get multiple Timewarp/Hero/Bloodlust etc. I'm sorry, but some raw stats will not outweigh multiple Hero uses. I highly doubt I'll remove that ring once I put it on.