O mangiar questa minestra o saltar questa finestra.
English translation: Either eat this soup or jump out this window.
Idiomatic meaning: Take it or leave it.

Occhio per occhio, dente per dente.
English translation: An eye for an eye, a tooth for a tooth.

Ogni bel gioco dura poco.
English translation: Every good game lasts a short while.
Idiomatic meaning: All good things come to an end.

Oggi in figura, domani in sepoltura.
English translation: Here today, gone tomorrow.

Ogni medaglia ha il suo rovescio.
English translation: There are two sides to every coin.

Ogni regola ha un' eccezione.
English translation: There is an exception to every rule.