Other than Monk, Swashbuckler, and Brawler, what are some classes that give you an AC bonus from having the class?
You have a few base classes, some of them have similar conditions for their AC bonus, such as being unarmored and not wearing a shield:
- Monk (and Unchained Monk);
- Self Perfection Psychic;
- Medium with a Guardian spirit;
These classes grant passive AC bonuses, that will increase your AC for no other reason than simply having the class and meeting the requirement (such as being unarmored). The Medium requires you to activate, at the start of a day, a specific spirit that lasts 24 hours, so I'm also counting that as a possible source of AC bonus.
You have many archetypes that grant certain AC bonuses, but considering the archetypes from a base class that does not already grant a bonus to AC, we got a shorter list:
- Sacred Attendant Cleric;
- Elemental Ascetic Kineticist;
- Esoteric Magus;
- Stonelord Paladin;
- Sacred Fist Warpriest;
But this is no exhaustive list, many of the archetypes from the base classes keep their AC bonus from the non-archetyped version of the class, so you can assume that a good amount of archetypes from those classes also have a bonus to AC.