Xxeric's Matted-fur Mask - because you can't beat +450 to mana click (still no item out there better that I know of), clicky works from inventory
Pendant of Discord or Pained Earring - Mana regen clickes, works from invenotry too when later upgraded
Assistant Researcher's Symbol - 2 useable slots neck and waist...plus detremental spell haste is hard to find and the item rocks. Plus it's a quested item, and most guilds probably won't charge RC or much for the Zun Tongue and Tunat's Tongue
If you look at my magelo, you will see I still wear 2 of the 3 items, and I use the 3rd as a clicky. They are that good (or hard to replace) and will last you for a long time.