I like apple best.不加the.这里的best是表示程度"最",如果best作表语,则要加the.例:
He is the best student in the school.
I like apple better(在上文中要有比较的对象)
take care of 是照顾
take good care of 是照顾好
有take better care of和take the best care of,但这并不是比较的用法,而是一种强调的语气.
Take the best care of yourself.多多保重!