When it comes to expressing one's opinion or preference, the phrase "left to me" can be replaced with several synonyms. One option is "if it were up to me", which implies that the speaker is not the decision-maker but is offering their personal recommendation. Another option is "in my opinion", which highlights that the speaker is giving their viewpoint but acknowledges that others may disagree. "To my mind" is another synonym that conveys a similar sentiment. Lastly, "from my perspective" or "in my view" both convey the idea that the speaker is offering their perspective on something. All of these synonyms are useful when expressing personal opinions or preferences.