According to LoveAntiques.com, the old VHS tapes gathering dust in your attic could be worth a fortune.
The most valuable tapes, it has to be said, aren't the battered copies of Peppa Pig or Four Weddings and a Funeral that most of us have kicking around.
"The most valuable VHS tapes are the ones deemed as one-offs, released in small batches within the 'video nasties' category and on micro-budget labels such as Knockout and Trytel," says the firm.
"Avoid common mainstream titles that were released on labels such as Cinema Club and 4Front, because these would have been mass produced and are worth next to nothing. Aim for films that have never been released on DVD or Blu-ray and are original ex-rentals."
Accordingly, the most valuable DVD in the world is Frankenstein's Castle of Freaks, a 1974 Italian horror film, at £1,500.
Old VHS tapes fall under the increasingly popular category of 'antech', or antique technology, covering post-1970s products that are no longer made.
If you think you've got anything valuable, your best bet is to start by looking on eBay, to get an idea of what it's likely to be worth. Depending on the likely value, you could either sell it there yourself, or contact a specialist dealer.
The fifteen most valuable DVDs
1. Frankenstein's Castle of Freaks (JVI) - £1,500
2. The Beast in Heat (JVI) - £1,200
3. The Legend of Hillbilly John (Rainbow) - £1,000
4. Journey Into Beyond (Citycenta GO) - £1,000
5. Lemora, Lady Dracula (IFS) - £900
6. Don't Open the Window (Films of the 80s) - £900
7. Flesh Eaters (Knockout) - £800
8. Black Decameron (Intervision) - £800
9. Curse of Death (Knockout) - £700
10. Farewell Africa (Fletcher) - £600
11. House of Perversity (GO) - £600
12. Anthropophagus the Beast (Video Shack) - £500
13. Hitchhike to Hell (VRO) - £500
14. Devil Hunter (Cinehollywood) - £500
15. Nightmare Maker, alternative orange sleeve (Atlantis) - £400