"As all get-out" is an informal expression, used to emphasize the degree or intensity of something. It is often used to describe something that is extremely good, bad, or surprising. There are many synonyms for this phrase, including "extremely," "exceedingly," "incredibly," "immensely," "outrageously," "unbelievably," and "unusually." Other phrases that could be used instead of "as all get-out" include "to the max," "to the fullest," "to the extreme," and "out of this world." Regardless of the specific words or phrases used, the idea is to convey a sense of powerful intensity and magnitude.