Risus abundat in ore stultorum - Abundant laughs in the mouth of the foolish - too much hilarity means foolishness
Roma locuta est. Causa finita est - Rome has spoken. The cause is finished
Romani ite domum - Romans go home!

Romani quidem artem amatoriam invenerunt

You know, the Romans invented the art of love

Rosa rubicundior, lilio candidior, omnibus formosior, semper in te glorior - Redder than the rose, whiter than the lilies, fairer than everything, I will always glory in thee
Rumores volant. / Rumor volat - Rumors fly. / Rumor flies
Saepe creat molles aspera spina rosas - Often the prickly thorn produces tender roses. (Ovid)
Saepe ne utile quidem est scire quid futurum sit - Often it is not even advantageous to know what will be. (Cicero)
Saepe stilum vertas - May you often turn the stylus (You should make frequent corrections.)
Salus populi suprema lex - The safety of the people is the supreme law. (Cicero)