Dragonslayer 4

The MSX1 version is definitely rarer and VERY SLIGHTLY more valuable, but honestly not by much. The few times I've seen it come up for sale (once loose, once CIB), it's gone for only a little more than the MSX2 version -- the boxed version sold for I think 4500 yen, IIRC? Which is like $42 or $43 American.

The MSX2 version has come up for sale considerably more often -- I'd say it's no exaggeration that I've encountered either auctions for it, or seen it on store shelves in Akihabara, at least a dozen times since I've started collecting -- but still sells for a solid 3000-4000 yen boxed.

In terms of which is the better GAME, the MSX2 version is HANDS-DOWN the one you want. But if you're looking for it purely as a collector's item, the MSX1 version just barely edges it out in terms of scarcity.

FWIW, I own the MSX2 game CIB, and also bought another copy of the MSX2 game CIB for a friend of mine for Christmas last year, but I only own the MSX1 game as a loose cartridge. As mentioned above, I did see the game CIB on the shelf at Trader #1 in Akihabara a few months back, but didn't have the money to buy it at the time -- and when I went back a week later to grab it, it was already gone.

-Tom