From Daughters of Fury:
The Angelfall Bow has a 3/day ranged trip using your ranged attack roll as the combat maneuver roll. Flying targets must make a DC25 Fly check or "plummet to the ground". It also has a 1/day counterspell vs any spell with the light descriptor.
The Amulet of Reverse Incantation lets you convert spells into their opposing forms 3/day as a free action:. Cure/Inflict, Haste/Slow, Alignment spells hit the opposing alignment, etc.
The Bog Boots are pretty niche, but they do allow for 135ft of dimension door and can really mess with movement math.
The Bosun's Call has 3 charges that refill each day, but you can use bardic performance rounds instead of charges. Good effects though. Auto-wake, messages, countersong, and climb/swim speed.
The Death Mask lets you use Speak With Dead without the normal save allowed for different alignments, and grants Alter Self to look like the living version of the most recent corpse questioned. Notably, it only needs "A head intact enough to fit the mask onto", unlike the normal spell.
The Evergreen Seed Pouch is like an Acorn of Far Travel, but for plant spells. The seeds in the pouch jump out and instantly form the required plants. It specifically says the plants grow regardless of the terrain and last the full duration of the spell. Probably some plant animating spells that are really good if you always have a target.
Fetish of the Frog Queen turns the will save on "targeted mind-effecting spells" into a fortitude save, 3/day.
The Goblet of Liquefied Cognition seems really abusable. If you are a spontaneous caster and feed it a spellbook page you get the spell onto your known list for 24 hours. Not a bad use for random captured spellbooks. If you are a prepared arcane caster and feed it an arcane scroll, it just memorizes it into a slot. If it's nonmagical writing, you "gain a complete understanding of the text's contents. This doesn't require an understanding of the text's language
". In all the cases, the knowledge fades after 24 hours, but that's enough time to abuse some eldritch knowledge.
Ironmorph Dust turns normal clothing into armor, or gives DR5/Adamantine if you already have armor on. It only lasts 5 rounds, but it shuts off druid casting! Unfortunately, it says they get it back at the end of the duration instead of the normal 24 hours.
The Murktouch cloak is 10 rounds of concealment and blindsight, and you can use touch spells/abilities anywhere in the radius of the fog it generates. The fog ignores wind or similar effects too.
The Nightbane quiver turns 20 arrows per day into tangible light, producing light as a Daylight spell for 5 rounds, bypassing DR of light sensitive creatures and counting as a force effect against shadows/wraiths. The arrows also retain any previous magical effects!
Quicksilver gloves Silver a weapon for 10 (nonconsecutive) rounds per day, and let you make an extra attack 1/day.
The Scourge Vial automatically flanks & dazzles a target with no save for 5 rounds, as well as forcing a DC 14 fortitude save vs sicken every round.
The Star Cinder is an amulet that shuts off resistance and immunity to an element of your choice for 12 rounds, as well as forcing a DC17 will save every round vs being banished. 60ft radius too. Elemental subtype creatures aren't effected though
While this one kinda sucks for its cost (45k and your glove slot), it wins on cool points: Stormcrusher Gauntlets let you catch and crush electrical attacks with a strength check of (10+1/10 damage). It also lets you do stuff with the electricity if you have mythic powers, but you have better things to do with your money if you are in mythic.
Sun Wukong's Puzzle Box makes you invisible, casts a dimension door 20 feet, and spawns a monkey swarm to distract people, all as a standard action. It lasts 10 rounds and is usable 1/day.