Dekahel
Porcano 2
Ohanabi
Master of Syougi
None of these are rare, they should be easily findable for under $20US or so.
-Rockman Battle & Fighter
This is really not rare, but it still costs a lot because of the name and because it was pretty expensive to begin with.
-KoF: Battle de Paradise
-Ganbare Neo Poke-kun
These were certainly not rare a few months ago, but the supply seems to have dried up to some extent on both of them. There's still plenty of copies out there in gamers' hands, though, so it's just a matter of finding someone willing to part with them, which won't be easy in the case of Ganbare since it's easily one of the best games for the Neo Poke.
-Big Bang Pro Wrestling
-Pocket Lover ~if~
These ones are somewhat rare. I don't think Big Bang sold very well originally, so there's not a lot of copies floating around; check <a href="http://www.gamechoiceclub.co.uk," target="_blank">www.gamechoiceclub.co.uk,</a> though, I think I saw ti there for cheap recently or maybe one of the other Honk Honk shops. As for Pocket Lover, it was very expensive like Rockman and not many importers touched it besides since it was so Japanese.
-Sorieke! Hanafuda Dojo
Another one that probably not many importers bothered with so your best bet would be to get it directly form Japan or maybe from Hong Kong. I don't know how easy either of those would be though; I've never seen the game for sale...but then, I've never looked for it either.
Of course, the only really good game of those listed is Ganbare Neo Poke-kun, that's a must-have title that no Neo Poke collection should be without. Rockman and Battle de Paradise are fun for a few minutes. The rest are pretty crap.