A British Raleigh bike with those horrible lever brakes. It was my father in law bike and he graciously handed it down to me. Soon after I stripped the brakes, fenders, chainguard, and rack. I changed the pedals for something with more grip and it became my mean transportation for 4 years. He shook his head while I did that, but after a while he rode it and he felt that it was much better ride than it was before.
I went on impossible distances from suburbia to downtown in traffic with that thing. I had to change sprokets because they were not all that good and it could not handle my mad cadence and they came apart often. I rode that behemoth of a bike to rugby practice - 10 miles each way - , school, girlfriends, friends, concerts, whatever ... did not need a car.
It was somewhat sturdy, but It could not handle the curbs all that well. That thing was not worthy of fixing after four years.
Then the fixie came along. Boy ... I felt like Fangio on that thing. It was so light and fast in comparison .... It felt twice as fast as the old Raleigh. I rode that thing to work and back, dates, general commuting, in the rain, etc.
That fixie had a bianchi frame that I got for peanuts. It had threaded touring tires and It was Ok since I did not know better. Repainted and whatnot, I raced the city buses to see if I could go faster than the already fast traffic.
Going to work I got a lot of respect from the guys since I was pedaling in that old fixie like mad. Only front brake, no tape on the bars, no gloves, no padded shorts, almost standing on the pedals all the time. The seat was all plastic and slippery and harder than concrete! It was one great way to get around and get a workout too. I had plenty stamina and I did not envy my friends with cars. None of my friends would be caught dead riding a bicycle for those distances - I was always the wacky one - and I thought nothing of spending a good hour and a half going from point A to point B. Needles to say that at that time I did not date much since my constant appearance was less than tidy and the girls on our circle wanted a guy with a car!!
Now in retrospective :
With those abominations of bikes I built up the stamina that lets me pedal my 24 gear 48 pound monster for 20+ miles at 18 miles per hour!