First two-wheeler - Schwinn Pixie I shared with my sister. We made the mistake of literally "sharing" it, that is, trying to ride it double, which broke the frame.
Next - Borrowed my older sister's Schwinn Collegiate (?) for a coupla years. Ran a stop sign at age 11 and got T-boned by a guy in a Falcon. Gave him the scare of his life, but bike and rider were fine.
First "my own" bike - Brand new Sears single-speed 26" canti-frame, Xmas 1971. Don't remember whatever happened to it.
1975-ish - Bought discontinued JCPenney 10-speed actually made by Jeunet (Simplex plastic derailleur, cottered crank, etc.), $50 brand new, when Schwinn World-*'s were going for >twice the price (same price per pound!). Repainted and rebuilt in '81 with alloy wheels, Super-6 (6-speed in 5-speed spacing) freewheel, etc. Fun fast bike for the money. Totalled in '82 when on rack on back of Nova, rear-ended.
1982 - Trek 813 "sport touring" - real handbuilt Trek from Waterloo. Toured Ireland on it with my gf (on her '75 Raleigh Gran Sport). Stolen when I lent it to my brother who actually thought you could safely lock a bike outside in Detroit. The one bike I truly miss
1986-ish - Built a bike from a Trek 900-ish racing frame (not new, but never built up), 600EX SIS components. This was my "go-fast" bike until just last year. Still in the basement, slightly disassembled
1989 - Used Ross Centaur sport tourer - Got about a $300 bike, nearly new, for $100 'cuz the seller "wanted a mountain bike". Fine! Sold it about three years ago for $125!
1992 - Used Trek 850; Wanted something more winter-friendly than the Ross. Turned out to be too "knobby" for my tastes. Became my wife's city bike until we got her a Trek 720
1993 - Used Univega Via Carisma - Had about 6000 miles on it. Replaced entire driveline, modernized to V-brakes, grip-shifters (sorry, but I HATE rapid-farts). Still my primary commuter bike; original wheels with studded Nokians for winter, "new" swap-meet wheels with road tires for summer. Weinmann concave rear rim has taken merciless punishment.
1998 - Wife FOUND a 1969 Robin Hood being thrown out. Missing a chain guard, needed new tires, gear indicator chain was bent up. Finish was in GREAT shape; just needed some oil. LBS owner gave me a Raleigh chain guard for it. Runs like a top now, and that black is soooo shiny!
1999 Xmas - "Santa" brought us a used Schwinn DoubleTime tandem (think entry-level hybrid turned into a tandem). Modernized with V-brakes, grip shifters. Our favorite way to go out together.
2000 - Bought a Mongoose Transport Folding 26" comfort bike on a 1/2 price sale at LBS. Totalled when T-boned by a Crown Vic two months later. His insurance paid full price (twice what I paid) for it, and they were on sale again, so I bought another one. Still have the carcass of the original in the basement
2003 - Found a '97-ish Cannondale R500 at a garage sale for $300. My first STI go-fast bike! But it's geared kinda low (26-36-46 chainrings? puh-leeze!), so I'm already spinning it out sometimes.
Jan 2004 - Found an EasyRacers SC1 (cheapo recumbent) at the swap meet, like new, $180. If I don't like it, I can turn around and sell it for $300.
I've found and bought and sold and given away a few others in between, but none that I would consider "my" bikes.