My wife and I have been discussing restarting our group without the kids (as they are scattered across three states). There would be four of us--two couples. I am thinking that I would start out as GM. While I think that we would eventually like playing a game like Trail of Cthulhu, I am not sure that is where we would start. I am thinking of one of two options (listed below).
Anglo-Saxon England + Swords & Wizardry Complete: I would create a setting that is based on the English kingdoms of the 8th and 9th century. I think our group would enjoy a elements of horror, mystery solving, and significant roleplaying. I would probably delete a few classes (assassin & paladin) and race options (gnomes, half-elves, half-orcs, halflings). I could make elves the equivalent of the Celts, who had enclaves on the western shores of the island of Great Britain. Instead of arcane magic, they could have druidic spells. I could play upon the recent conversion of the area to Christianity and have magic-users relying on the powers of the old--now forbidden--gods, while clerics rely on the power of the "one true God."
Whimsical Horror-Tinged Fantasy + Swords & Wizardry Core: Here I am thinking of Robert Lynn Aspirin's Myth series, Piers Anthony's Xanth books, or Terry Pratchett's Discworld novels, at least in flavor, along with whimsical horror elements of Jonathan Carroll (check out his Land of Laughs, one of my favorite novels).