Most gamers have old games and old consoles packed away somewhere, even if it's in a storage container or somewhere in the attic. And for the most part, those games and consoles are worth more for their nostalgia value than they would be if you were to put them up for sale on an auction site.

Every now and then, though, someone comes across their old NES or Atari, checks out the games that they have, and discovers that they're worth thousands of dollars. Sure, popularity plays a part, which is why you can expect at least $100 if you have The Legend of Zelda: A Link to the Past with the original box and manual. At the same time, though, rarity is also an important factor and part of the reason for Zelda's popularity is that so many people had it.

And so with that in mind, let's jump on in and take a look at some of those retro games that hit that sweet spot between popularity and rarity - and which are worth a hell of a lot of money as a result.

1. Stadium Events (NES): $1,750 - $3,500

Stadium Events is often called the NES's rarest game, although it's more common in Europe than it is in North America. European PAL versions are worth around $3,000, but North American NTSC versions are worth a lot more - as one lucky woman found in 2013 when she bought a copy in a goodwill store and then sold it on for a 17,000% profit. A sealed copy in its original packaging changed hands for over $30,000 and the box alone is worth up to $10,000.


2. Tetris (Sega Genesis/Sega Megadrive): $3,000 - $15,500

Tetris is such a popular game that you might be wondering how it's possible for a copy of it to be as rare and as valuable as it is. It all comes down to a copyright dispute between Sega and Nintendo, who owned the exclusive distribution rights for the game. Sega only ever made ten cartridges and they were only owned by the development team. One signed cartridge sold for a cool $1 million at auction back in 2011.


3. Air Raid (Atari 2600): $3,000 - $33,500

Air Raid is a pretty standard game when it comes to Atari 2600 games, and it's the rarity of the game that makes it such a collector's item. While it's not immediately clear how many copies were originally made, there are said to be only a dozen copies left out in the market. The actual value of the game depends on whether you have the box and the manual, but the cartridge alone is worth a couple of thousand bucks.


4. Lakers vs. Celtics and the NBA Playoffs (Sega Megadrive): $10,500

It's the PAL version that's particularly sought after because the North American NTSC cartridge |is much more common. That's perhaps partly because basketball is more popular in the USA than it is in Europe. You also might be out of luck if you have the cartridge but not the packaging because it's the packaging that makes it so collectible. The game was never released in Europe due to licensing conflicts, and while a couple of hundred copies made it out into the hands of collectors, only thirteen of them are actually accounted for.


5. Red Sea Crossing (Atari 2600): $10,500 - $13,500

If the title of this game sounds a little biblical, that's because it is. Red Sea Crossing takes the concept of Frogger and gives it a remix, allowing players to guide Moses across the Red Sea. What's interesting about this game is that it was first found at a garage sale and to begin with, no one was sure if it was legitimate. It turns out that only 100 copies were ever produced by Inspirational Video Concepts, and only two of them have ever gone up for auction, both attracting over $10,000.


6. Blockbuster World Championships II (Sega Megadrive/Genesis): $11,000 - $16,500

Remember Blockbuster Video? This game was published as a joint effort between Sega and Blockbuster and contained two games: Judge Dredd and NBA Jam Tournament Edition. Used for gaming tournaments across the world in the early 90s, the cartridge has such a high valuation because only a couple of them still exist.


7. Birthday Mania (Atari 2600): $14,500 - $33,000

This game's a quirky addition to our list because it's only valuable because it was made to order. Back in the eighties, punters could contact the developers to order customized copies for people's birthdays. It was a big hit 35 years ago, but few copies remain in circulation so it's no surprise that it's so valuable.


8. Gamma Attack (Atari 2600): $500,000

Only one copy of Gamma Attack was ever made by developers Gammation Products, primarily because they were mostly known for their peripherals and other fun console add-ons. Originally thought to be a myth, it's owned by super collector Anthony DeNardo and is set to be worth a cool half a million.


It's not just rare games that you need to look out for: you should keep your eyes peeled for accessories too, as many of those are also worth money. For example, Blockbuster's old Nintendo 64 rental kits are worth around $4,000 as collector's items if they're in good condition with the instructions and the foam casing.

So now you know what the market is like and what's worth what, perhaps it's time for you to take a look in your attic to see whether you have any of these games lying around. Remember that these are just a few of the most valuable, but there are plenty more games out there that are worth a few hundred bucks to the right collector.

One good way to get a feel for the actual market value of your games is to search them out on eBay and to look at completed listings. Then you can look at both 0what people are listing the games for and what they're actually selling for, which will give you a much more realistic idea of what you can expect. Good luck.