一も二も無く[ichimonimonaku] unhesitatingly
一言二言[hitokotofutakoto] a word or two
一石二鳥[issekinichou] killing two birds with one stone
一二に及ばず[ichininioyobazu] right away
一姫二太郎[ichihimenitarou] It's good to have a girl first and then a boy

うり二つ[urifutatsu] as alike as two melons (two peas in a pod)
黄道十二宮[koudoujuunikyuu] twelve signs of the zodiac
二度[futatabi] again
最小二乗法[saishounijouhou] least-squares method
三十二分音符[sanjuunibuonpu] 32nd note

御蔭様[okagesama] (somebody's) backing
御客様[okyakusama] guest
お子様[okosama] child (someone else's)
お生憎様[oainikusama] that's too bad (ironical)
御待ち遠様[omachidoosama] I'm sorry to have kept you waiting

御疲れ様[otsukaresama] thank you
御母様[okaasama] mother
ご苦労様[gokurousama] thank you very much for your ...
御馳走様でした[gochisousamadeshita] That was a delicious meal (said after meals)
様を見ろ[zamawomiro] serves you right!