Finding the perfect synonym for the term "most goofproof" is not an easy task. However, some possible alternatives could include "most foolproof," "most fail-safe," "most idiot-proof," "most seamless," and "most effortless." Each of these words implies an element of simplicity or ease, indicating that a particular task or situation is unlikely to go wrong. Whether you're looking for a synonym to use in a professional or personal context, these options should give you a range of choices to suit your needs. Remember to choose the word that best conveys the intended meaning and tone of your message.