A looooong time ago (possibly during 3.0e days), and back when I was posting on Monte Cook's boards, I created a variant Ranger that could pick up "Ranger Talents" (to use Pathfinder's current Rogue to give a perfect example of what I did).
In it, I had the old Favored Enemy options, but then also had some different options.. like the following:
- The ability to pick creatures from the bestiary (instead of a creature type) to have bonuses against. They were added to a list, capped by your ranks in Knowledge (nature).
The ability to swap them out with time and a skill check, and feats for expanding your max known were available.
This was typically more relevant since you could wait and choose creatures (with a skill check) as you encountered them.
- The ability to gain a bonus against a specific target. To get this bonus, you needed to observe the target in combat (similar to the assassin), or out of combat (took longer), or even the option of Survival checks (reading tracks) or Gather Information checks (word of mouth, typically for humanoids but also "local legends") to gain the bonus before even meeting the creature face to face.
This was more of a Hunter type of ability, so was automatically relevant all the time, as long as you invested time/checks into it. This also had additional options with the ability to have multiple targets, quicker learning about the target, etc.
Basically Quarry, but as a more "main ability" type thing.
- Similar ability with favored terrains, where you spend time and skill checks to adjust your "survival training" for the current environment, and adjust your ghillie suit to gain proper camouflage, etc.
Get extra stuff in line with more movement, reroll perception checks or never surprised, etc.
"Hunter's Bond" effect of allowing you to give your allies a little fast movement and ignore terrain penalties screams "ranger" to me too.
Since most of these abilities were more uniform, I went with more "gain extra crit range or multiplier" or "cause status effect" or "ignore penalties or gain retries" stuff, instead of just pure attack and damage, or skill bonus. That way you didn't always have +10 to attack and damage or skill against a particular creature/terrain or set of creatures in combat, but you could get a +5 bonus to those, and deal crippling effects, or gain fast movement and "act on surprise rounds" in terrains, etc.
This sound like the kind of stuff you are talking about?