Can't forget immortality, which is shown pretty clearly in the movies with Bilbo and obviously Gollum, but also:
The Ring enhances the wearers "presence" and ability to influence others. Sam observes in the books how elf-like and majestic Frodo has become by the time they get to Mordor due to carrying the ring. At around the same time as this scene, we see Frodo impose himself on Gollum and the book remarks how powerful he looks and how his words seem to influence Gollum.
Later on, when Sam is carrying the Ring, this effect is noticed even more clearly when the orcs see his shadow not as that of a small hobbit but that of a powerful elf lord

The effects we've seen are on the pretty low race of hobbits, and would be even greater in someone of numenorian descent, but assuming it stops at those: Boromir would become an immortal, ultra charismatic leader who can also become invisible to everyone but the Wraiths and other spirits, which he can pretty easily take on 1v1