Image: A collection of retro video games, controllers and consoles © AP photo

There's a rumor going around that nobody's buying video games anymore. The truth is they're just not buying the new ones as much these days.
Sales of new video game hardware, software and accessories fell 24%, to $848 million, in September from $1.1 billion the same time a year earlier, according to NPD Group. That's 10 straight months of declines despite releases including Electronic Arts' (EA) "Madden NFL '13" and "Battlefield 3" and Take-Two Interactive Software's (TTWO) "Borderlands 2."

Sales of games alone, including computer games, fell 14%, to $547.3 million for the same period. Nobody's buying hardware, such as Microsoft's (MSFT) Xbox 360 or Sony's (SNE) PlayStation 3, which saw sales fall a whopping 39% last month. (Microsoft is the publisher of MSN Money.) The gaming world is eagerly awaiting the release of Nintendo's (NTDOY)Wii U console in November, but even that may not be enough to bring video games back to their pre-recession, pre-Apple (AAPL) iPhone heights.

Even online gaming has taken a hit. Facebook (FB) blamed its slow revenue growth on users not playing as many games from FarmVille maker Zynga (ZNGA) as they used to. That downturn led Zynga to do away with 13 of its games and lay off 5% of its staff earlier this week.

Not that a small but well-funded niche of gamers cares. On full display at the Retro Gaming Expo in Portland, Ore., last month, the retro gaming community pores through bins of old Atari, Colecovision, Nintendo and Sega games searching for hidden gems and old childhood favorites. Gamers pay more now for hard-to-find titles, such as "War of the Gems" or "X-Men: Children of the Atom," than they did when the games were released.

Retro gamers also still plug away at vintage arcade machines such as Bally Midway's half video game/half pinball machine "Baby Pac-Man" or Atari's aging movie tie-in "Indiana Jones and the Temple of Doom." The community, a mish-mash of late baby boomers, Gen Xers and Gen Y, still loves these games and, thanks to their newfound adult income, still shells out to get their own copies.

With help from the folks at Denver vintage game dealership J.J. Games and its Price Charting blog, we've come up with 10 games still raking in the cash years after their initial release. Time will tell if old copies of "Guitar Hero" or "Just Dance" will do the same:

10. "Atlantis II"
Format: Atari 2600
Highest price ever paid: $5,000

It's not that hard to get a functioning Atari 2600 or any of the consoles or adapters that played its games. It's far more difficult to get your hands on this game, which was never sold commercially -- it was offered only as a prize to players who maxed out the high score on the original Atlantis shortly after its release in 1982.

Developer Imagic asked for players to send in photos of their high scores, but eventually grew tired of seeing America's youth blow through their prized product. They sent out "Atlantis II" to the kids with the best scores and defied them to do the same with this version, which had faster enemies. To save money, Imagic sent out game cartridges with the exact same casing and labels as the original. The only way to tell the difference is to turn on the game, look at the score font and clock the bad guys' speed. As one might imagine, this makes buying and selling the game a bit of a hassle, but given the price it can fetch, it's worth the legwork.

9. "Mr. Boston Clean Sweep"
Format: Vectrex
Highest price ever paid: $7,200

It takes a special kind of geek to shell out the value of a used car on an unpopular game sponsored by an unpopular liquor and played on an unpopular console.

The Vectrex was a "portable" game console introduced in 1982, just before the video game crash of 1983. It used a controller the size of a cable remote to play black-and-white games consisting mostly of opposing geometric shapes on a cathode-ray-tube screen the size of a stack of iPads. It was crude, cumbersome and not much to look at, but defunct liquor company Mr. Boston saw fit to create custom versions of the game "Clean Sweep" with its logo on the front and the mascot's top hat replacing a vacuum as the game's main character.

Only about five of these games are known to exist today. The Vectrex, however, is much easier to find after its creators put the console and its software into the public domain in the mid-1990s. Anyone who buys a copy of this game will have no problem tracking down a homebrew version of Vectrex to play it on. We're just not sure why they'd want to.

8. "Neo Turf Masters"
Format: SNK Neo Geo
Highest price ever paid: $8,000

Again, if you want to sell to old-school game geeks, it pays to get esoteric.

The Neo-Geo was a high-powered, cartridge-based arcade game when it debuted in 1990. Its games, including "Fatal Fury," "Metal Slug" and "Samurai Showdown" were fast, richly colored and far more dense than the 2-D games of its time. It was also a home console whose games were identical to the arcade versions and blew away competitors such as the Sega Genesis and Super Nintendo.

Unfortunately, its $400 to $650 price tag was prohibitive at best, while the $200 cost of each of its games was considered outlandish to folks paying $35 to $60 for SNES and Genesis games. "Neo Turf Masters" came along toward the end of the console's U.S. heyday in 1996 but has been a tough find in its console version for years. Gamers haven't exactly been denied a chance to play it, though, as a version was included in an SNK compilation for Sony's PlayStation 2 and PlayStation Portable and Nintendo's Wii, as well as in the Wii's Virtual Console.

The average player's not going to pay you a Hyundai Accent for this console game, but there are a bunch of retro game collectors out there who won't be as stingy.

7. "Blockbuster World Video Game Championship II"
Format: Sega Genesis
Highest price ever paid: $8,000

Hey, remember Blockbuster?

Time was, you'd go to the store with a $5 bill in your hand and come out with the game of your choice and a box of Mike and Ikes. Then you'd inevitably get charged $5 more when you couldn't beat the game in time and sneaked it back into the dropbox late.

Blockbuster loved this relationship with gamers and, in 1995, held in-store competitions where players could compete against each other on "Donkey Kong Country Competition" from Nintendo and "Blockbuster World Video Game Championship II" from Sega. Players could win the former, but Blockbuster was told to destroy all copies of the latter, which contained versions of the "NBA Jam Tournament Edition" and "Judge Dredd" games. The store managers were willing, but their disaffected, scantly paid '90s employees were totally weak and sneaked some copies out of the stores.

Years later, with Sega no longer making consoles and Blockbuster now just a costly branch of Dish Network (DISH), the "Blockbuster World Video Game Championship II" cartridges can breathe free and sell to the highest bidder.

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