Mortal Kombat Trilogy (U) [!] <- should work. It was one of the first games to run in the first place.
Conker (U) [!] <- wont run, too big & special microcode
Ridge Racer 64 (U) [!] <- wont run, too big.
CastleVania (BOTH) (U) <- First one seems to crash, I think the 2nd is too big.
Mega Man 64 (U) [!] <- wont run, too big.