* A mad-bomber-type bomb-focused alchemist that loses the mutagens and some of its other stuff for additional bomb-related features
* Artificer variant of Alchemist that builds gadgets and such
* A poison-focused Alchemist that can craft poisons more quickly/on the fly, boost poison DCs, and the like
* Edited in: An ooze-focused alchemist whose mutagen turns them into an ooze-like form
* Some manner of plant-controlling Druid that isn't restricted to elves-only
* Some manner of plane-based Oracle whose mystery-powers operate based on a fundamental connection to one of the planes. This could probably be accomplished with a set of mysteries instead of an archetype, but I think it still fits the thread's general theme.
* CG/LE Paladin to cover the other two corner-alignments (with the CG having anti-law and the LE having anti-chaos since the LG covers anti-evil and the CE covers anti-good)
* Summoner archetype that constructs Golems/constructs
* Summoner archetype that specializes in summon a particular type of Outsider (Archon/Angel/Agatheon/Azata/Inevitable/Aeon/Kami/Psychopomp/Elemental/Prot ean/Devil/Kyton/Asura/Rakshasha/Oni/Daemon/Demon/Qlippoth, Also one for Nightshades even those are technically undead)
* Summoner-as-a-necromancer archetype that summons undead and has a customized undead thing instead of an eidolon
* Some sort of staff-specialized wizard that's better at using spells from staves (DC boost, spend spell slots to cast spells the staff can without using stave charges) but suffers in terms of other casting flexibility
* A white necromancer who can animate non-evil undead (perhaps by summoning up ancestors / only being able to animate those who were willing prior to their death / using some manner of metaphysical trickery to get around the 'wrapping up a positive-energy soul with negative energy is evil because of how it affects the soul' thing)
Those are the ones that spring to my mind as concepts that I've wanted to play / have in a game that I found haven't been available in official material (so far as I know). Third party stuff is doing pretty well on the white necromancer one, but I'd still like to see official support for the role.