God Quest. I said I'd run it, and I think it'd be fun. The premise: the more believers, and the stronger their belief is, the more power the god has. The players are members of a pantheon of a pantheon with a relatively small number of believers, around 1000 total, with 100 true believers, 250 moderate believers, and the rest minor believers.
God Campaign.
Summary:
Been thinkin about it.