I've rarely met a Japanese gaming commercial I didn't like. Retro ones, especially. I think it's because so many of them are equal parts earnest and, well, bat-shit crazy.
The one below, for the Famicom Disk System version of Metroid, is a good example, although it's definitely more serious than silly.
This ad was nabbed from the recently launched tumblog known as FC.CM ("a collection of commercials relating to the Nintendo Famicom"), by the way.
If you decide to pay it a visit (and I sincerely hope you will), be sure to check out the commercial for the Korean version of the Famicom/NES (called the Hyundai Comboy).