I'm starting a campaign filled with undead and evil dragons. My GM has given me the go ahead to make a character that hunts them (as they are super common). I don't really want to do a paladin as I've played one recently and Ranger doesn't seem to fit what I want. My question is: are there any other classes or archetypes that grant favored enemy like abilities?
Half-Orc hateful rager. But that just grants the favored enemy ability (with some nifty interactions with rage).
Ranger and Paladin are pretty much the go-to for your concept.
Certain clerics builds could work with variant channeling.
Inquisitor make great monster hunter. Bane and later Greater Bane will add significant damage. Judgments are also going to be incredibly useful. Most people concentrate on the offensive judgments but there are also some good defensive ones. Also having 6 levels of spells and full caster level means you get your buffs earlier and they last longer.
Skill wise they also have monster lore and can get improved monster lore for some really high rolls to identify the specific type and its weaknesses.