[noun] + をおいてほかに + いない [noun] + をおいてほかに + ない
をおいてほかに~ない means "there is no one but X", "nothing but X will do": the noun before をおいて is the only one good enough. It goes straight after a noun, and the sentence ends in いない for people or ない for things.
The sentence praises: the noun is the best, the one that can't be replaced. With someone to blame, use しかいない or いがい以外にいない instead.
ほかに can be written ほかに他に, can take は (ほかには), and can drop out altogether. The pattern is formal and emphatic, at home in speeches, recommendations and writing; しかない is the everyday way to say "only".