I suppose this is more of a “what’s my favorite weapon enchantment” answer, but:

The Spirit Bow with the Projection enchantment; you can shoot through walls, doors, and enemies, so you can:

• get a head start on defeating enemies before they even get to you;
• defeat enchanted statues without having to do battle;
• use one enemy as a shield to defeat another (e.g., shoot past a snake to defeat the crab behind it)
• Defeat larger or shoot-and-run enemies on the other side of a doorway, while they can’t get to you.

In ARranged PD, it would have to be the Eldritch enchantment that makes enemies turn tail and run.