2. "Umbrella" (feat. Jay-Z) (2007)
Thank Britney Spears for the song that changed everything for Rihanna: The "Toxic" singer's label turned down what would become a megahit for the Barbadian star, transforming her into a full-fledged pop heavyweight. Co-written by Tricky Stewart, Kuk Harrell and The-Dream, the song is a unique piece of music: a song that marries a heavy rock undercurrent to vibrant rhythm guitar and a perfectly catchy R&B-pop hook. The song ended up being Rihanna's first Grammy win and a Number One hit in many countries — but at a price. Many claimed there was a "Rihanna curse" as the U.K., New Zealand and Romania were hit with heavy storms as soon as the single topped the charts in each country.