Перевод - Французский-Английский - la meilleure chose qui me soit arrivée

Pour moi il faudrait dire plutôt "The best thing that has happened to me" et ne pas rajouter "ever" donnerai comme sens "la meilleure chose qui me soit jamais arrivée".

The best thing that happened to me.

Well, I think the same that ''ever'' is not in the Spanish version...

Hi girls,

When translating we need to make the meaning sound natural into the target language.
In English when we refer to something that happened (up to now) we don't use Simple Past Tense, but Present Perfect since the action was in the past but is valid until now.
When using "has/have happened", "ever" comes naturally.
Therefore "that has ever happened to me" means exactly "qui me soit arrivée" of French and "que me ha ocurrido" of Spanish even if the words are not "exactly" the same, but those needed for the target language to keep the meaning the source has.

I agree with your explanation, Lillian, and therefore have voted this translation as correct.