*Clothing*:
MIC:
Ankh of Ascension CL 17 (Gives a bonus to CL for divine casters.)
Anklets of Translocation CL 7 (Good for getting out of grapples, I’m sure it has other uses also.)
Armband of Elusive Action CL 3 (Allows you to avoid AoO)
Artificers Monocle CL 5 (If you’re an artificer or can cast detect magic it allows you to identify items without having to spend the 100gp material component)
Belt of Battle CL 9 (gives you extra actions)
Casting Glove CL 11 (allows you to store items such as rods, wands etc. for quickly retrieving them.)
Crystal Mask of Spellcraft CL 7 (this item was actually titled “of psicraft” but I ruled that due to psionic/magic transparency this applies to spellcraft also, gives a bonus to spellcraft checks)
Dispelling Cord CL 5 (adds a bonus to dispel checks)
Gauntlets of Ghost Fighting CL 13 (Allows you to damage incorporeal enemies and ignore the 50% miss chance.)
Healing Belt CL 3 (At the lower levels wands of vigor or faith healing are much more efficient, at the higher levels these allow you to heal between battles.)
Ring of Arcane Might CL 8 (+1 to CL)
Ring of Arming CL 10 (Good if you need to get your armor on and off quickly)
Ring of Artifice CL 12, 14, 16 (Gives bonus artificer infusions)
Ring of Spellbattle CL 14 (Read the description)
Scout’s Headband CL 9 (Pretty cheap, it gives you true seeing for one minute once per day)
Seven Veils CL varies (each veil gives you immunity to one or another of the prismatic veils. Useful if you're facing an IotSV or a prismatic wall etc.)
Spare Hand CL 11 (Very useful, allows you to carry wands/rods. If you power it with a 1st level infusion you can store and retrieve items as a free action.)
Third Eye of Dampening CL 3 (Reduces numeric variables of spells etc. to the minimum. Functions once per day. Very useful)
Third Eye of Sense CL 3 (Allows you to see and hear at a distance. The location has to be either familiar or an obvious one. Pretty useful.)
Wand Bracelet CL 6 (Allows you to store and retrieve items quickly)
DMG:
Ring of Spell Storing CL 5, 9, 17 (The use is obvious)
Ring of Sustenance CL 5 (Only need two hours of sleep)
Rings of Wizardry CL 11, 14, 17 and 20 (Bonus spell slots are nice.)
Monk’s Belt 10 (Add wisdom to AC)
Gauntlets of Rust CL 7 (protects equipment from rust.)
Hand of Glory CL 5 (Give up a throat slot, gain a ring slot.)
Headband of Int/Periapt of Wis etc. CL 8 (Gain bonus spells)
Ioun Stones CL 12
Necklace of Adaptation CL 7 (Protects you from harmful vapors and allows you to breathe underwater.)