I know this is an old thread but I just ran into it while searching for something else. I can't believe you guys are going so crazy over AK: Shinobi World. This game is not hard to find at all (comparatively). I've sold two in the last month and a half on eBay. U.S. versions of course. There is one thing that is a *fact* and most serious SMS collectors should know already. The hardest two U.S. SMS games to find, hands down, are Sonic and Buster Douglas. No other game is even close. I have personally come across multiple copies of every other U.S. SMS game in the last six months alone. There are no other U.S. SMS games that sell for over $50 on eBay every single time they are offered. Including the last Christmas season I have only seen three Buster Douglas games and one U.S. Sonic on eBay. The Busters went for at least $80 each and the Sonic, which was in a lot with a Power Base and a couple other games (also sold by someone I know, which burned me up. Afterwards he was like "I wish I would've known you needed it, we could've traded" ARGGGH.) went for *$250*!!! And the Sonic before that which was sold by iteself went for $350. I know some of you will say eBay is not a good example. I don't agree. These games are almost never in game stores. Finding them in the wild is like winning the lottery. So realistically eBay is the only place all of us have equal access to that has these kinds of games.



As for an additional list of the next rarest games, here's my opinion:

Group 2:
Super Monaco GP
Power Strike

Group 3:
Slap Shot
AK: Shinobi World
Castle Of Illusion
Strider
Spider-Man

Group 4:
Alf
Golden Axe Warrior
King's Quest
Montezuma's Revenge

That's just in my experience but I do go through about 200 SMS games every month so there is a solid basis there. That's about it. If you can find these games getting every other game for the system should be easy.