You want a cursed item that will truly piss off players?
One that changes their gender, or sexual orientation.
Trust me, expect eye-popping action.
Are you kidding? The Belt of Change Gender is the most popular cursed item in my gaming group and people are always trying to find ways to introduce one into our campaigns.
It's probably best not to think too hard on the "why" aspect.
Bedroll of Kingly Comfort
Cuts the standard time needed for sleep (to regain spells, hp, etc.)by half. Additionally, anyone laying prone on the roll is at a -4 vs Sleep spells.
Boots of squeaking
These boots look like a worn pair of boots of elvenkind, but once put on they cannot be taken off without a remove curse spell. Whenever the wearer rolls a stealth check, they take a -10 on the check as the boots begin to squeak very loudly with every step. These boots squeak on any surface, be it grass, stone, dirt, wood, etc.
What do you think?
Love it. Isn't there an old addage about if your shoes sqeak you stole them?
Zweihander of stupid
Minor cursed artifact
This +3 greatsword comes with an additional special ability, once per day for 1 round, it is treated as having an additional 5 foot of reach. Command word: "grow long".
When used it reduces the users intelligence to 2. No save.
The scroll of bees by Nicomeus Cage.
Three summon scrolls that easily (low dc) allows multiple giant bees to be summoned. 3-5 depending on the party. They attack the summoner first, and then other targets. They persist until destroyed, upon which time, each giant bee turns into a small honey filled bee hive. Which drops from height and crack open, releasing normal sized killer bees in great numbers.
The honey is delicious.
Ring of unsteady retribution
Looks like ring of retribution. Detect magic reveals it to be ring of retribution. But when put on, it instantly explodes, dealing 12d12 points of damage with a radius of 30 ft. Anyone 5 ft outside the radius takes 1d6 points of fire damage every turn until they die or it is extinguished