Mine (Aruiteru would be 2nd, though):
1. Kotatsu no Uta ~jyuken story~
Yossi + Eri + Risa = ftw. The song is great~ I freaking love it just because of how their voices match so well.
2. Yuki / Ai Anata ≧ Suki
Ai solo (kinda...)!! It's sooo pretty <3 Too bad Risa's talking didn't do well in this. Ah, still, Ai saves it.
3. Wa~MERRY Pink X'mas!
Simply cute! I loved it live, I love it in the album version too!
4. Samui kara Fuyu da mon! ~Doumokou mo Maissu yo Mikitty~
At least Mai sounds nice.
5. Kira Kira Fuyu no Shiny G
Ew. Kiiiiiiinda cute, but cute seriously doesn't fit Reina to me (neither sexy, but blah).