nonpareil
Better than all others; tiny colorful candy sprinkles.
Nonpareil means without equal, unmatched, absolutely the best at something. When you call someone or something nonpareil, you're saying nothing else even comes close to it.
The word comes from French, where non means “not” and pareil means “equal.” A nonpareil performance by an Olympic gymnast is one that no other gymnast could match. A chef might be called the nonpareil master of French cooking, meaning no one else reaches that level of skill.
You might read about a nonpareil achievement in science, like when scientists first landed a probe on a comet. Or you could describe your grandmother's apple pie as nonpareil if it's truly the best you've ever tasted and nothing else compares.
The word suggests uniqueness at the highest level. Something nonpareil stands alone at the top. While “excellent” or “outstanding” means very good, nonpareil means there's literally nothing else like it in quality or achievement.
Interestingly, nonpareil is also the name for tiny colorful sugar balls used to decorate cakes and cookies. Bakers use this name because the decoration is meant to look especially fine, though this meaning is quite different from the “unmatched excellence” definition.