1. 1990 Nintendo World Championships: Gold Edition NES cartridge (NTSC-U): This NES game was a Nintendo Power contest prize, promoting the famous Los Angeles Nintendo tournament popularized by the film The Wizard. 26 copies were created and given to lucky winners. The estimated value of this game is $10,000+.

2. Kizuna Encounter, NEO GEO cartridge (PAL): This is an interesting rare game because versions other than the PAL version are quite common. It is estimated that 12 exist in all. Recently, one of these sold for $13,500. Only 5 copies are known to have surfaced in the market.

3. 1990 Nintendo World Championships: Tournament NES cartridge (NTSC-U): This game is identical to the above mentioned game, yet it was a gift to the 90 finalists of the competition. This game is worth $4,000+.

4. Pepsi Invaders, Atari 2600 cartridge (NTSC-U): This was a promotional game created by Coca Cola to celebrate its trouncing of Pepsi in the early 80s. 125 of these exist, and are valued at $1,200+.

5. Bangai-O: Prize Edition, Sega Dreamcast CD (NTSC-J): This game was given out to winners of a Japanese tournament. Only 5 copies exist, so it is difficult to value the game, but it is worth over $1,000.

6. Stadium Events, NES cartridge (NTSC-U): This is a relatively well-known rare title by anyone that has investigating game collecting. There are 2000 copies of this game. It was released, recalled, and re-released as “World Class Track Meet” with the Power Pad. It is valued at over $1000.

7. Air Raid, Atari 2600 cartridge (NTSC-U): This $3500 game is known for having very limited release numbers and an insane looking blue cartridge with a handle.

8. Virtual Bowling/SD Gundam Dimension War Virtual Boy cartridges (NTSC-J): These games are equally rare and are from the fallen Virtual Boy system. They are valued at over $1,000 each.

9. Atlantis II, Atari 2600 cartridge (NTSC-U): This game is rare because it was never officially release. This was a more difficult follow-up to a competition featuring "Atlantis," because people did too well at the competition. It is extremely rare and worth $1,000.

10. Metal Slug, NEO GEO cartridge (NTSC-U): Most of my friends thing that Metal Slug is the defining game of NEO GEO. It is so fun and so quirky. It is obviously still popular, since it will cost you around $1,000 to get it.

All Maniac Mansion cartridges for North America for the Nintendo Entertainment System - were made with a "deranged" action enabled: Two of the six playable characters would see nothing wrong with microwaving the hamster. Nintendo censors initially overlooked killing of the hamster, but cartridges for other markets removed the hamster killing ability.

From the article on Wikipedia: http://en.wikipedia.org/wiki/Maniac_Mansion

NES port and The Expurgation of Maniac Mansion

In 1990, a version was published for the Nintendo Entertainment System (NES) in North America and Europe, but in a heavily censored form in order to comply with Nintendo of America (NoA) and Nintendo of Europe's policy. However, NoA initially overlooked the ability to microwave the hamster to death. Many thousand copies of Maniac Mansion had shipped before NoA noticed and demanded its removal. However, as there was no second printing of the game, all North American cartridges include the "hamster" and the "microwave". The PAL region NES cartridges of Maniac Mansion have the hamster-microwaving ability removed.

Another NES cartridge would be the unlicensed version of Tetris by Tengen - which IMHO was MUCH better than the official Nintendo licensed version. http://en.wikipedia.org/wiki/Tengen_(company)

Tengen faced another court challenge with Nintendo in 1989 in copyright controversy over Tetris. Tengen lost this suit as well and was forced to recall what was estimated to be hundreds of thousands of unsold cartridges (having sold only about 50,000).

It's too bad too - I really liked that version, but the video store shipped it back.

This website might help to give you a good idea of what games are going for around the Internet:

http://www.videogamepricecharts.com/

That being said, Panzer Dragoon Saga and Radiant Silvergun are two of the most valuable games on the Saturn. Both go for upwards of $100 last time I checked. For the PS1, Suikoden II is supposed to be quite rare.

canon pixma ink

I saw on Tv
1. 1990 Nintendo World Championships: Gold Edition NES cartridge (NTSC-U): This NES game was a Nintendo Power contest prize, promoting the famous Los Angeles Nintendo tournament popularized by the film The Wizard. 26 copies were created and given to lucky winners. The estimated value of this game is $25,000 good condition and including in the box.

lots of rares for every console brother printer ink

some of the most valuable games are the 1st zelda games the very first final fantasy and o most any game for the nes and snes un-opend

One rare game that I know of is called Bubble Bath Babes for the NES. It is rare because it is one of the few "adult" games to ever be made for the NES, and because of this, it was never authorized by Nintendo. However, it was sold for a short time unlicensed. It is a tetris-like game that contains some 8-bit nudity. They usually sell for around $400-600 dollars on eBay these days.
http://www.racketboy.com/retro/bbb.jpg

Another rare game is Stadium Events, also for the NES. It is the most rare commercially sold NES game. What makes it rare is the fact that it was recalled shortly after it was released. There are just under 800 copies in existence, and they commonly sell for over $1000. There is one on eBay right now for over $1200 for the cartridge only!