Someone who immediately charms or impresses you is a dazzler. Your funniest, most sparkly and engaging friend could be described as a dazzler.
To dazzle is to stun with a bright light or an impressive personality, and a dazzler is anyone or anything who does this. A fabulous fireworks display is a dazzler, but so is the student in your French class who can speak six languages fluently and manages to be witty and charming, too. Dazzler, from dazzle, shares a root with daze meaning "be stunned or bewildered."