Define successful as you see fit, whether it be how much money you netted, how you were able to help someone, what the flip allowed you to get, etc, etc.

I've only "flipped" one bike. I got a Trek Y22 with a nice work stand, lights, shoes, pedals, clothes, trainer, etc from a garage sale for $200. I was able to sell the bike for $600 and kept everything else. I passed on the shoes and pedals to my brother to get him started, still use the the lights occasionally, use the workstand all the time, and have been able to use a couple of the jackets it came with. All in all, I made $400 and got to keep a bunch of good stuff.

So what's your most successful flip?