The antonyms for the term "most basket-case" refer to individuals who are composed, stable, and level-headed. Such antonyms include terms such as calm, collected, cool, and unruffled. A person who is calm can be described as being serene, peaceful, and tranquil while someone who is collected is self-controlled, composed, and balanced. Similarly, an individual who is cool is undisturbed, relaxed, and untroubled, while a person who is unruffled is unflappable, poised, and in control. These antonyms signify a sharp contrast to individuals who are often referred to as "basket-case" that are considered to be mentally and emotionally unstable.