Potomac Airfield's long-running website mixes real general-aviation information, Washington-area airspace access, flight training, and airport history with a sustained campaign of jokes about bureaucracy, spies, marshmallow Peeps, and directed-energy weapons.
Laurent Besset's solar-balloon site documents ultralight balloons heated only by sunlight, with construction notes, flight reports, payload estimates, historical material, multilingual pages, and wonderfully earnest W3C validation badges.
Marc Zeitlin's unofficial Cozy builders pages preserve a homebuilt-aircraft community that moved onto the web and a mailing list in 1995, accumulating technical references, builder reports, newsletters, suppliers, performance data, and hard-earned safety information.
Paul Freeman's Abandoned & Little-Known Airfields has been documenting vanished airports since 1999 and now contains thousands of entries assembled from maps, aerial photographs, directories, memories, and contributed research.
ConcordeSST.com preserves a dense technical and historical record of the supersonic airliner, including material assembled while Concorde was still flying.
Kirksville Regional Airport uses the identifier IRK, which is a perfectly legitimate aviation code and also an alarmingly accurate three-letter mood for anyone who has ever driven Highway 63 in bad weather.
Eric Dumigan's AIRIC site preserves decades of Canadian aviation photography, airshow reports and family aviation images in a long-running independent archive.
PlaneCrashInfo has been cataloging aviation accidents since the late 1990s, preserving a blunt, hand-built database that reaches back to the earliest years of powered flight.