Daisy is a character in Nintendo's Super Mario Bros. series. Her first debut, I believe, was in Donkey Kong, where Mario had to climb and use hammers that floated in the air to avoid barrels and rescue Daisy, who was being held prisoner by the giant ape Donkey Kong.

Daisy's next appearance was in the Super Mario Land series for the original, bulky grey Game Boy, where various monster posed as Daisy in various castles throughout the land.

Our next viewing of Daisy is as the typical "hot chick" in a movie, with that movie being the Super Mario Bros. movie.

Daisy's next debut is Mario Tennis for the N64, where it is made clear that Daisy and Princess Toadstool (Peach) are two completely different people.

Daisy's latest appearance is in Super Smash Bros. Melee, where she's merely a color change for the Peach character.

Overall, Daisy isn't a very exciting person. No trademark items, no appearance in the cartoon show, no major involvement in any video game plots, nothing. She's just some brunette that Mario used to hit on before he established a preference for blondes.