For centuries, secretive bands of acolytes have kept Albion safe, performing the ancient and mysterious rituals that ward the land against dreadful supernatural forces. Join your comrades in song, ale and battle. Perform secret rites at the equinox while maintaining your cover as harmless drunken eccentrics. Keep back the darkness with long-forgotten magic, and when that fails, hit it on the head with a stick. Grow a beard, wear a silly hat. Join the Morris.
Shall we dance?
Unlike most things I write, this isn't a proposal for a new system, just a campaign. Morris is a sandboxy suburban fantasy. You play Morris dancers tasked with maintaining supernatural wards via rituals, and taking down anything creepy that manages to slip through, while maintaining secrecy.
Given the premise is quite silly, I personally feel it would tend to work best with a pretty straight approach that takes it all seriously. A silly version could work too, of course. It strikes me that something like WoD would be a reasonable system, not least because it's not that different in premise. FATE could also work, assuming I ever work out how to run it.
Because you're fairly ordinary people otherwise, there's plenty of scope for incorporating more mundane things going on, personal arcs, inter-character stuff and so on.
As a very British setting, it's distinguished from a lot of urban fantasy because nobody's carrying guns. It doesn't matter how urban fantasy it is; nobody goes around carrying guns in Britain. Big sticks, though, you can get away with.
I picture the supernatural stuff as all a bit mysterious to everyone. Nobody's entirely sure how all this stuff works, including the magic they do to keep out the darkness. What's vital, what's mere ritual and habit? Some part of this folk song helps fend off evil, but are the doo-rallies and the atonal singing really necessary? There are many disagreements, schisms and power struggles between rival Morris troupes, let alone other groups with broadly similar aims.
The main enemies of the Morris are supernatural forces, but human antagonists also present a threat. This politician brings in music licensing; that concerned citizen brings a noise complaint. A drunken gang here decides to disrupt a dance and threatens the magical stability of the whole county. More worryingly, dabblers in occult mysteries may wish to channel magical forces to their own ends, and risk unleashing terrible things on the unsuspecting populace. There's room, too, for some more neutral actors: indifferent immortals or whimsical spirits who bear no malice, yet are not allied to the Morris. They must be bargained with, placated, entreated or browbeaten to attain the Troupe's ends.
The pic is adapted from Morris: a life with bells on which is a really good film, you should watch it.