Nutshell: Player choice, but most lean to getting the Skill Point.
In general, for most players, giving the Crown to Toll is considered the better option. It gives a Skill Point bonus, adds a more complete narrative of the history of the continent, and allows the Bishop to live.
That being said, the Bishops Ring is a top tier item. Strong Death Protection, defense and one of the few items to give a +2 to a stat. For Clerics and Mages, that +2 PERS turns into a decent amount of magic. It also gives a nice reputation bonus, for those that need it in game, or those that are competing for a total score game.
The drawback to ring is that it's use is best limited when fighting enemies with death damage, or no elemental damage. Against other elements, you're likely going to swap out for rings with a matching elemental resistance. You can also get a +2 PERS item later in the game, if you complete the game peacefully. Additionally, by the time you can get the ring, you've likely already killed off the worst of the liches, and have completed the Pits, the two places that benefit the most from death protection.
It's a tough choice.