An idea I've been coming back to a lot...the Ranger lacks something centrally thematic, right? Sure, you can fix casting. Subclass bonus spells and spell prep help a lot. Adding some better spells to the list (I mean, a 3rd-level AoE spell that does 3d8 non-scaling damage? Really?) helps, too. But it doesn't fix the underlying problem.
So here's an idea: drop the Beast Master subclass, and make the Companion a core class feature. I still think it needs revision, but if you want something to really make the Ranger stand out, "The Ranger is the one with the fighting animal buddy" sure beats, "the Ranger gets bonuses to rolls for which no rules actually exist."
Here's a sketch:
Same proficiencies & hit dice & PHB
- Magic: 1/2 caster, spells prepped = 1/2 level + WIS, 2 subclass bonus spells per tier
- Beast Companion, rewrite it to make the action economy less confusing (and not rely on your bonus action at all)
- Most of the Beast Master improvement schedule just becomes class features (e.g. at 11th level), scrub some of the Natural
- Explorer/Favored Enemy stuff to make room for subclass features
- Every subclass should have at least one Companion-related improvement on its schedule, maybe 7th level?