I hear the Rose Bowl Flea Market is world famous. It ought to be, if for no other reason than sheer size. The second Sunday of every month, vendors surround the stadium selling everything new, used, old, horrible, fabulous, grotesque or sublime.
In proving the adage, "One man's trash is another man's treasure," you may have to dig deep--or walk a long way. Use your imagination, wear comfortable shoes, and bring plenty of cash.