Regarding Mike Abson suggestion: me wonders about throwing compatibility lists in the docs folder of MAME/MESS SVN, for each major system. PHP files where one defines zip name/game name/last SVN revision that the game was tested/status (works yes/partial/no) /emulation notes. I know, most people here puts this info in XML, but I want a flashy table that's readable by everyone with their browser :P (and note: I'll put this type of files on my site anyway, if you bring a giant nay on it for whatever reason).
Anyway:
Umihara Kawase ShunBlack screen
Castlevania ChroniclesWorks better than the correlated x68k emulated version, including steady 100% and samples. lol.
CharumeraWorks. Unique RPG/sim involving a "yatai merchant", obviously unplayable without JP knowledge.