I am interested in the Ninja Gaiden....
Here are the doubles I know I have... I may have a few more.
Some are loose and some come with cases... I'll have to check for you if you are interested in any of these
Champion Wrestler
F1 Circus '91
F1 Triple Battle
Populous
Racing Spirits (Irem Vol 6)
Power League II (vol 20)
World Circuit (NC91004)
World Jockey
Pro Yakyuu World Stadium
Power Eleven
Power League IV