Jason's quest for the Golden Fleece has a lot of similarities to pretty much every quest story there is. The basic plot—hero goes in search of some valuable thing—is pretty widespread. One of the most common comparisons to the myths of the Golden Fleece is the legend of the Holy Grail. The most popular story is that this artifact is the cup that Jesus drank from at the Last Supper and also the cup in which Joseph of Arimathea caught some of Christ's blood when the martyr was entombed. The “Quest for the Holy Grail” is pretty essential to Arthurian legend, in which knight after knight heads off to distant lands to gain the magical cup. Learn more Grail lore here.
Plenty of other heroes have gone on quests for golden objects as well. One example is Jason's Greek hero buddy, Heracles, who went off to fetch the Golden Apples of the Hesperides. Another example is the fairy tale The Golden Bird, which was recorded by the Brothers Grimm. In this story, a prince sets off to capture a priceless golden bird that has been stealing his father the king's golden apples. (For the full story, click here.) Another myth is the legend of El Dorado, the legendary City of Gold, which had Spanish explorers traipsing all through South America in hopes of becoming fabulously wealthy. (Click here to learn more about El Dorado.)