I've only had one accident in a car.
I was driving home from school one day in my big american 4000 lb FWD boat (94 Pontiac Bonneville) and it was snowing. The roads had not been cleared yet. I'd never driven in the snow before so I didn't know just how easy I had to take it. I was fine on some back roads where there were just sharp 90 degree turns. Then I approached a bend while doing about 15 mph, and for a little bit, it seemed okay. Then all of a sudden, terminal understeer. I was going straight towards the curb. PANIC. Full right lock, more understeer. Slammed on the brakes and they came right back up.
Oh shit... I gritted my teeth and braced for impact with the curb. The front left wheel, cranked way over to the right, took pretty much all of the impact. When I came to a stop, I got out and surveyed the damage. Immediately I noticed a hissing sound coming from the front left tire. Aww crap... I only had 2 miles to go and really didn't want to try changing the tire in the snow. So I hopped back in the car and started driving a bit. Steering seemed okay, so I took it all the way home. A few minutes after I got home it was completely flat.
Then when my father came home he took a look at the wheel and noticed something that, in the heat of the moment, I had not: a small section on the edge of the front left rim had sheared off, a piece about an inch wide and a few inches long.
On my bike I've had a few incidents, none of them really major and none involved anyone else or any cars but all were really scary at the time, and all of them involved me being an idiot.
The first time I was in a parking lot practicing for the motorcycle license test. I got the idea that I might try pulling a wheelie. I sat there, stopped, revved it up a bit, and dumped the clutch. It seemed like the front wheel may have come up a little bit, but the engine just pretty much bogged. I tried again with a little more revs but a similar result. Once more I tried with a lot more revs. The front end immediately came up and I very quickly had trouble keeping from falling off the back. With my death grip on the bars and the way I had gripped the throttle, I couldn't let off the throttle. Still holding onto the bars, I jumped off the pegs and tried desperately to hold the 300 lb bike up as it went completely vertical and then fell on its left side. As it fell, I fell on my left knee and scraped it up a bit. Needless to say a few parts on the bike needed replacing after this one.
The second time I was showing off a bit in my driveway and along the side of the house. On the grass, approaching the driveway, I was doing about 15-20 mph. At that moment, I suddenly realized how high and steep that edge of the driveway is, and I think I must have grabbed a handful of front brake while on the grass. The front end washed out and I went down just as I got onto the driveway. I wasn't wearing any protective gear at the time. Needless to say, that hurt, a lot.
The third time around I was heading into school. There's this one sharp right hander on campus that I loved to take at speed and get the bike leaned over a lot. I knew that, doing about 30-32 mph, I could scrape my boot on that turn. So this time, I figured I try it at about 35 mph and try scraping the peg. I approached the turn, neutralized the throttle, and leaned it in. It all happened really fast. Next thing I knew, I was sliding on the pavement on my stomach watching my bike slide in front of me. I got up and immediately noticed a sharp pain coming from my right knee. Road rash. The bike also suffered some damage, the worst of which was the slightly bent bars which made riding it home that day a little difficult. Surprisingly enough my leather jacket suffered almost no damage.
I have to say, though, I'll never regret getting the bike and I plan on continuing to ride throughout my life. Also, I'm sure that, if my bike had better tires, I would have gotten through that turn just fine.