Perhaps you recall a little earlier, when I gave the Three Graces of Eliptony as Completism, Obscurity, and Sheer Madness. Eberhart's compendium, a massive 1100-plus page tome subtitled "Primary Access to Observations of UFOs, Ghosts, and Other Mysterious Phenomena," is the South Magnetic Pole of Completeness. For every location in the entire North American continent north of the Rio Grande (plus Hawaii and Greenland), Eberhart gives bibliographical cites for its accumulated history of weirdness, broken down chronologically by type from Acoustic Anomaly to Witch Trial. My old stand, Oklahoma City, for example, has listings for Automatic Writing, Crisis Apparition, Dog Mutilation, Fall of Fish (Oct. 5, 1953, cited to Doubt magazine), Fall of Shark, Spacecraft Inventor (one Otis T. Carr, fl. 1957-1959, given the telegraphic notation '=hoax'), Telephone Anomaly (2 cases listed, with three cites), and 28 UFO entries ranging from 1946 to 1975, broken down into seven subcategories (CE-1, CE-2, CE-2 with Men In Black, CE-3, DD, NL, R-V -- Close Encounters of the 1st-3rd kinds, Daylight Discs, Nocturnal Lights, Radar-Visual contacts). And so on and so on, from Allakaket, Alaska (Humanoid Myth: "bushman") to Winter Park, Florida (six cites from Animal ESP to the 1895 Skyquake). An index groups all the sightings by type, and then by observer. If this massive compendium has a flaw, it is the inevitable one of datedness -- by now 25 years of High Weirdness have gone past Eberhart's terminus. That also makes it hard to find, and expensive -- mollpeartree gave me one for Christmas in 2000, much to the confusion of her family.
Honorable Mentions: Eco, Umberto, Foucault's Pendulum; Ellis, Richard, Imagining Atlantis.