When we use the phrase "recommend itself", we are referring to something that speaks for itself, that is so good that it needs no further endorsement. There are several different synonyms that can be used to express this idea, depending on the context. For example, we might say that something "makes a case for itself", "stands on its own merits", or "speaks for itself". Other possibilities include "advocates for itself", "vouches for itself", or "sells itself". Regardless of the specific words used, the idea is always the same - that the thing in question is so outstanding that it requires no additional explanation or endorsement.