I enjoy the Oriental Adventures book for Advanced Dungeons & Dragons First Edition and have played it quite a bit in my past, to the point my book is falling apart. In the past while running games out of this book, I've stepped it up or taken it to the next level by speaking in Japanese for Non-Player Characters. I've designed custom sheets for the game and even tried to supply the table with props for the game.
When I was living in New York, everytime we played, we ordered Japanese take out to help get in the mood of the game. I'd like to think the players enjoyed themselves as it helped really set the mood of the game that day, and helped them get in the frame of mind for some great roleplaying.
I know quite a few people dislike this book, because of various reasons, but I really enjoyed this book from the first game I played when I was kid, up to this day as a man. I know this game was redesigned for the 3rd Edition D&D, and I never used it, but the best thing came of the game, when it was turned into the Legend of the Five Rings. Great game, with an awesome system still being played by lots of people who enjoy this type of gaming.