I know alot of people who are fans of Niigaki Risa tend to like the pairing of Takahashi Ai and Niigaki.
Rightfully so, 5th Gen is my favorite Generation by far, and it isnt soley because of Gaki. The Bond that all 4 girls had in 5 gen in my opinion is by far the strongest throughout the generations. I was planning on doing a post revolving around the 5th gen so im going to keep it short and say that I am personally a TakaGaki fan.
But at a very close second is the GakiKame combo. These 2 girls bring out so much laughter and energy out of anyone in Morning Musume currently, what is there not to like about them?