Cleaning out your closet or attic can reveal valuable items, whether sentimental or collectible. So what could an antique relic from your attic fetch at an auction or from an antique dealer?

Gobankingrates.com has compiled a listing of the top geeky collectibles that sometimes have more value than most people realizing and pack the potential for lucrative returns for their owners.

The list points to the fact that it's not just long-lost relics or rare antiques that can lead to a big payday. Sometimes, items from the recent past, including toys and other merchandise, can skyrocket in value for cultural reasons, for example.

"How much your geeky collectibles are worth can be subjective and might depend on a variety of factors like condition, rarity, age and demand," Gobankingrates.com says. "You’ll likely need multiple rare and valuable collectibles to fetch $1 million, but it could be worth giving it a try if you’ve got a collection."

These are the top geeky finds, in ascending order:

12. Sports Memorabilia

The value of some items in this marketplace are constantly changing, depending on how players and teams perform on the field. The Super Bowl victory by the Philadelphia Eagles this year, for example, drove up the price for a bobblehead doll quarterback Nick Foles by 900 percent, from about $30 to $300.