Unequaled
Part of speech: adjective
Definition: Unmatched, superlative, the best ever done, record setting.
Unique
Part of speech: adjective
Definition: Being the only one of its kind; unequaled, unparalleled or unmatched.Of a feature, such that only one holder has it.(disputed) Of a rare quality.(disputed) Unusual.
Example sentence: Neuroscience is by far the most exciting branch of science because the brain is the most fascinating object in the universe. Every human brain is different - the brain makes each human unique and defines who he or she is.