A Fascist PotterverseA mash-up of Harry Potter, Neverwhere, Misfits and others.
Secretly, all manner of supernaturals lurk in our world. Wizards are top of the heap, using their magic to enforce domination and keep the ordinary folk in line - the most benign of the wizarding community believe the mundanes must be magically lobotomised, controlled and kept quiet. The Magocracy is a priviledged elite, using the lesser supernaturals and mundanes as pawns to maintain their luxurious lives.
The player characters are low-lifes of one sort or another - petty criminals who meet through community service, perhaps - who discover they have supernatural abilities. They discover the lies of the Magocracy and decide where they stand.
Cowboys - in space!Tales From the Star Wars Cantina / Firefly-esque Planet-of-the-week, western-style antics with Galactica-style FTL allowing for a bigger scope than a few planets and moons - all grungy tech and frontier attitude.
A fairly casual game of episodes, with an emerging overall plot drawn from players' goals.
War of GodsThe world shakes under the angry feet of the gods themselves!
These "gods" reflect the beliefs of the people - and reinforce those beliefs with superpower actions. They are in fact powerful extra-planar entities - demons, devils, archons, etc. - and unique monsters.
Their temples function as gateways to the outer plane where the god of the temple resides. Generally, each tribe or clan has its own god, but some allied clans and tribes have co-operating gods.
Tribes and clans have political priesthood and gods (generally settled), or shaman (more often in nomadic people).
Magic is a power of the gods - mortal and player character magic will be very limited.
Demikind races live in walled/fenced or hidden settlements, warring against the dangerous monsters of the wilds. There are few "civilisations" - just cities in key points, supported by agriculture, thriving due to geographic isolation.
A few nomadic peoples outside the civilisations are living in barbaric conditions, constantly struggling against monsters.
As the people of the settings have expanded and populations have grown, their lands have come into contact with each other - and their beliefs have clashed! The gods with brook no rivals! Holy war with the added terror of nuclear-war-level deities.
The player characters will be a disparate band of adventurers / outcasts who see the coming anihilation, and can try to stop it, or aid one side or another.