I thought the Onimusha sword controller for PS2 was kind of dumb because it looked like a sword but had the same D pad and buttons as a normal PS2 controller. It had some kind of internal sensor that could tell if you were swinging the sword, but it didn't work very well.
Total mind trip I remember that, we had 10 of them in stock for years at the local game store I used to work at. We sold one to this anime fan that bought everything that was Japanese related. And another one to a guy who had just bought the game so i bundles it up for him. But he came back like 30 minutes later complaining and wanting a refund. The other 8 stood on the shelf collecting dust and fading while the box edges started crumbling.