noun, noun or participle which takes 'suru', transitive verb, noun which may take the genitive case particle 'no'
Internet slang derived from おすすめ, used in a playful or emphatic way to recommend something.
See also: オススメ
この曲、オヌヌメだよ！
This song is my recommendation!
初心者にオヌヌメの設定を教えて。
Tell me the recommended settings for beginners.