This list was made in collaboration with the Rollplay community over at /r/itmejp! A huge thanks to everyone who gave suggestions. As a disclaimer, some of these may have come from other sources online. If one of these originated with you, let me know and I'll be happy to drop you a credit.
For the Extra Life session I ran for Rollplay, donations had unlocked a Priest in town who could sell players random magic item enchantments. After paying, the player would roll 1d100 and the listed enchantment would affect the item offered to the Priest.
1. Resistant to: 1 Fire – 2 Cold – 3 Necrotic – 4 Radiant – 5 Thunder – 6 Acid – 7 Lightning – 8 Poison
2. Vulnerable to (1d8 above)
3. Stat counts as if 19:
1 Strength – 2 Dexterity – 3 Constitution – 4 Intelligence – 5 Wisdom – 6 Charisma
4. Stat counts as if 6 (1d6 above)
5. Item gains sentience and a randomly rolled alignment (1d3 for each part)
6. (Gen rolled this one!) 1/long rest, sprout seraphim wings. Gain a fly speed equal to walking speed for 5 minutes. Blind all who look directly at you. Count as an Angelic creature for this duration.
7. You no longer need to breathe.
8. 1d6 times per short rest you can burp at will and produce a large toad. This toad can carry a short dictated message to a destination you've visited and deliver the message to a target you've spoken with in the past. The toad hops out of sight and then travels instantly to an out of sight location within hopping distance of its destination.
9. You can speak with cats. Others who hear the conversation will only hear loud meowing.
10. You can speak French. French is not spoken in the Forgotten Realms.