Found during a board game: Martin Johnson Heade
Found in a Wisconsin living room: Van Gogh
Found in rubble by a peasant: the Venus de Milo
Found at UC Berkeley, then promptly undersold: Sargent Johnson
Found in a garage sale: Andy Warhol
Found in a basement: Picasso
Found in a thrift store: another Picasso
Found in a thrift store: Jackson Pollock?
Found in a thrift store: Ilya Bolotowsky
Found in a couch: Venetian painting
Found in walls: Mayan murals
Found in walls: a Dada mural
Found by accident on the internet: Thomas Kinkade's "Disney Dreams Collection"