Edit
Japanese soft drink apparently made from turmeric[1]. It became famous among anime fans worldwide because its commercial[2] aired during the original broadcasts of Mahou Shoujo Madoka Magica's episode 2 through 4 and was also left in gg's fansub releases. (gg even added the commercial back into episode 5 even though it didn't air). The apparent hilarity of the commercial, and the fact that it drastically contrasted with Madoka's overall atmosphere, contributed to its popularity among fans.
Note: Do not make this a "copyright" tag, as it is an object/meme, not a series.
External links
[1] http://en.wikipedia.org/wiki/Turmeric
[2] http://www.youtube.com/watch?v=PD-_oLjmCGY