I don't know if this has been suggested before, but I thought: Why not combine Vanilla and Clan War? Such a game would require plenty of trickery and guile. Like Clan War, it would have balanced sides (the number of which being dependent on how many players there are; perhaps 2 sides for smaller games, and 3 for bigger ones), except that there are no PRs, as in Vanilla, and everyone is a villager associated with a respective clan e.g. East Villager, South Villager. In larger games, a Neighbour Assassin role to speed things up could be included. The win condition is simple. It is to lynch the other clan(s) down to 1 villager. When that happens, that Clan has been exterminated and that last member dies as well, or maybe convert to a buffed role, or even to another Clan (I'm not sure if it's possible to code that). I think it will be fun as players will have to claim to be with the majority Clan in order not to be lynched, and the balance can be easily tipped with mislynches. This leads to players constantly switching their claims of which side they are on, something which has to be pulled off skilfully to be successful. Even when the sides are balanced (e.g. 2 vs 2), someone will have to fakeclaim and try getting an opponent lynched so as to avoid a stalemate, which I'm sure nobody likes. The fact that teammates aren't revealed to each other makes it more difficult to plan and execute such operations.
...eh. Vanilla is praised for it's simplicity, this doesn't seem that simple in all fairness. Not sure if the whole concept would be able to take off, since there's no way for either side to confirm or deny the legitimacy of a claim. While that may be good for players like me, it's obviously not going to be that appealing to other players. But it could solve the problems with Vanilla being too "slow". If anything, I can help code. PM me if you want to.
This has the possibility of leading to endless stalemates if there are 3 sides. if there are two then yes it would work but at that point it would just be regular vanilla. 4 sides could also end in a stalemate as well. All in all the fact that this could come to many stalemates it is probably not the best idea for a theme.
Thanks for the input, and to Matt Ayala, for that offer too. At the moment, with the issue Beast raised of potentially having too many stalemates, I'll keep this in the brainstorming stage, and try to find a creative solution without sacrificing simplicity. I initially was going off on the assumption that people would rather take risks than reach a stalemate but I realise that may not hold true for all.