Many thanks is a common phrase used to express gratitude or appreciation. However, there are several synonyms that can be used to convey a similar sentiment. Some of these synonyms include "thank you very much," "much obliged," "many thanks indeed," "grateful," "appreciative," "thankful," and "obliged." Each of these phrases can be used in different situations and contexts, depending on the level of formality or emotion you wish to convey. By using synonyms for many thanks, you can add variety and depth to your expressions of gratitude.