As the old saying goes, one person's trash is another person's treasure. What's the best thing—chairs, roller skates, old electronics—you've ever found that someone else had thrown away?
The summer when I was 17, I was in the summer pre-college art program at CMU (this one was 6 weeks, and during the school year, I was in the Saturday program). One day, I was walking down the hallway to one of my classes and saw this beautiful old table sitting in the hall with a piece of paper marked "trash" taped to it. I really liked it and wanted to rescue it. So I talked to a couple of my teachers, and they said to go for it, and I wrote a note on the paper saying I was claiming it. Someone else wrote that I had to take it that day, so I called my mom, and she brought the minivan, and we rescued it. That thing is kind of a beast to move, since it's big, and I've had to move it at least 4 times.
A few months later, in my high school art class, we were supposed to be painting old chairs for some project, and I asked my teacher if I could paint the table instead. So I brought it in and basically drenched the thing in rainbows. Each leg has a base color and then some sort of decoration (handprints, spattering, clouds, and stars). There's green around the edge of the table, and then the top is black with a bunch of magazine cutouts decoupaged around the middle. Yes, the table looks rather ridiculous, but it's my table, and I'm proud of it and how goofy it looks. Right now, it's up in my craft room with a couple puzzles on it.