oshimen
a #1 favorite. Often used by fans of japanese multi-member music groups as their #1 favorite of the group. It comes from the Japanese 'oshi' to push/support, and "men" is short for the engrish "menba", so the member one supports the most.
"My oshimen changes daily, depending on my mood. Ususally it's Takahashi Ai, but that's strictly from Morning Musume. That's not including AKB48."