I don't fancy myself as much a collector as I do a person who adopts wayward video games, and as such, a few rare gems have landed into my meager game library. some are worth more than others as far as resell value goes, but some are priceless as far as sentimental value. In my wallet, my copy of Contra Force is worth much more than my copy of Anticipation, but since Anticipation was bought for me by my now deceased aunt, it is valued as much if not more than that copy of Contra Force. For many collectors it is merely about money though, and those gamers are always on the lookout for incredibly hard to find gems. Today I thought I'd mention a few of the hardest to find titles on the NES, and a few of them won't cost you more than a car payment. You may also notice a little trend with some of these titles.
Little Samson - Taito - 1992: Little Samson is a gem of a game, it controls well, has a decent challenge, and it looks and sounds as good as anything on the NES. It would have been one of the biggest sellers on the NES if not for one important thing: it was release in 1992 and many gamers had already jumped ship to the SNES by that time. it's been spotted on eBay for around $160.
Bubble Bath Babes - Panesian - 1991: Nintendo watched over the content on their 8-bit console like a hawk, and anything that was the least bit questionable didn't get the coveted Seal of Quality on the box. Panesian knew their adult themed games would never get over the hump, so they made pirate carts. Very few copies of their games ever made it into the wild and so they are highly sought after. copies of this one can run up to $1,000 but a reproduction cartridge is currently in circulation through http://retrousb.com .
Caltron 6 in 1 - Caltron - 1992: Today we see multi game collections all the time, and most of the games in those collections prove to be horrible. It was the same during the time of the NES. This may explain why pretty much all of the multicarts released on the NES were unlicensed. Caltron released this pile in 1992, a full year after the debacle that was Action 52. While this one fares only slightly better that it's 52 game counterpart, neither seems worth the money. These will set you back up around $300, so tread lightly.
Snow Brothers - Capcom - 1991: A great arcade port typically sold quite well on the NES, which makes the rarity of Snow Brothers even more peculiar. For whatever reason, though, the NES port of Snow Brothers did not sell, and now commands prices easily above $100.
and now a few more affordable NES rarities:
Contra Force -Konami - 1992: It wasn't really a contra game, and it was a bit mediocre, but Contra Force commands anywhere from $30 - $60 online.
Adventure Island 3 - Hudson - 1992: It isn't extremely expensive, but it can be hard to track down. Copies of this one run between $25 - $50.
Bomberman 2 - Hudson - 1992: The original game typically costs no more than $10, but the sequel came along much later in the NES life cycle, didn't sell as well, and runs between $30 - $60 online.
I know I neglected to mention a lot of very rare games, but I didn't want to bore you with a list of games that most folks know about like Action 52, Stadium Events, or The Miracle Piano. If you would like a more detailed list of really rare games, drop me a line and I'll be happy to pass you one.
If you didn't notice, most of the really rare games I mentioned were released at the end of the NES life cycle.