From what I've read, FFXII and most of the games released around the time of it up until now have the best translations. The NES/SNES Generation's terrible translations are well documented as well as FFVII and Tactics. VIII-X are all said to have been rushed as well or dropping meanings that were important such as Witches being turned to Sorceress in VIII as well as Edea/Ultimecia's speech being different, IX was terribly rushed and Kuja apparently had a unique poetic speech pattern that was lost in translation, and FFX had to deal with syncing the voice clips which according to interviews was a nightmare. Apparently Auron was everyone's favorite character in the FFX English translation dub because his outfit covered his mouth and thus his dialogue could often be translated without butchering the dialogue to make it fit.