At my dad's company picnic when I was maybe 5-6 years old, my ticket came up for the semi-grand prize, a ten-speed bike. Well, considering I wasn't even tall enough to touch the handlebars, I asked if I could trade. So I took the SW Land of the Jawas playset. Most considered it a stupid move; I did not. Still have all the non-cardboard parts to it.
Won a "free" (you guys are right, not really free, since postage was needed) He-Man figure from some chocolate company.
Came in first place in a youth street chalk drawing contest (drew Roger Rabbit, after having been disqualified the previous year for my Spiderman using my own chalk colors ) and won a local business gift certificate.
I won a couple raffles at my jobs (mugs, flower arrangements, shirts, gift certificates, books, etc.)
Fast foods contests (for "free" food, but never money).
Most I even got was $5 on a lottery ticket (not much luck on those).