I've got a desire to play in either of the following games. Each is a bit out of the ordinary, but both could be a lot of fun with the right GM and group of players:
1) Blood War planar fiend game.
While I know the Blood War isn't a concept in Golarion cosmology, it wouldn't take much effort to incorporate it.
The PCs would play fiends(either unique creations or using ones that already exist) taking part in the war.
We could either be allied to one faction, or mercenaries akin to the AD&D Yugoloths selling our services to the highest bidder.
2) Undead game, two different game ideas.
PC would be undead of one sort or another. There's two concepts for the actual game:
The first is the PCs are either low ranking Blood Lords in Geb, looking to move up the ladder of power, or are looking to become Blood Lords.
The other idea is a bit more complicated. The game would be set during the Shining Crusade, where the PCs are lieutenants of The Whispering Tyrant. There's two outcomes here:
Either the PCs are able to turn the tide vs the Crusade, thus changing the history of Golarion. We would then play through the centuries until present day.
The other outcome would be that despite being the 'good guys' we still lose, and get locked away with Tar-Baphon inside Gallowspire.
We would then be released during the events of Carrion Crown, unleashed upon an unsuspecting and unprepared Golarion.