I have owned, as an adult, 25 bicycles. I've sold 7, broken 5, had only one stolen, and thrown away one. Of the 5 frame breaks: 3 were mountain bikes, 1 was a road bike I dropped in a hole while riding and bent the frame and one I ran into the side of a car (got 4 days in a hospital, 6 months in PT and about $4k in compensation). I've had 3 tandems, 2 of which I still own. I still have 11 of them including 2 mountain bikes (one hardtail and one full suspension), 1 multispeed crusier bike, 1 folder, 2 touring bikes, 2 road bikes, the 2 tandems and one fix gear. The oldest one in my fleet is from 1984. The newest is about a month old.
I didn't like a Univega Sportour (the one I dropped in a hole), an old Biachi mountain bike (wrong size) and an old Libertas tandem (way too short and floppy). The one I threw away was an old foundling that I made into a fixed gear. I found a better one and made that into a fixed gear.
The ones I regret loosing was the Univega Vivatour I ran into the side of a car and a very bright, very shinny aluminum cruiser style bike that was stolen out of my garage on Christmas Eve, 1998. On the plus side I did get a Stumpjumper Pro out of the deal - possibly the best bike I have ever owned!