White Knight Chronicles

You must complete 50 quests and get rewarded the "S" rank when completing them. The S rank comes from completing the game with minimal flaws. This will take a lot of time and will be tricky without a team (as the quests were designed to be completed with teams). The easiest way to do this trophy is to get up to a high guild rank and then go back and complete the lower level quests. The standard quests (yellow) are mostly easier to S rank than the additional quests (blue). You will however have to complete at least a few additional quests to S rank in order to get this trophy as only 49 of the standard quests are completable without a team. It has been confirmed that the patch with additional quests can be downloaded without having to play the game online first which makes this trophy easier.

Here is BrightBlade's guide for suggested quests to S rank Solo, with point margins and GR.