One of a kind
Definition 1 of 1
Pro Tip 1/3Exclusivity Emphasis
Used to highlight the unique and rare qualities of a person, object, or situation. 
The handcrafted vase was one of a kind, attracting collectors from all over.
Pro Tip 2/3Positive Connotation
Often implies a positive quality, suggesting something is special or admirable. 
Her one-of-a-kind approach to solving problems made her a respected leader.
Pro Tip 3/3Non-replicable
Implies that the object or trait cannot be exactly replicated or copied. 
His painting style was one of a kind, impossible to imitate.