There really couldn't have been a more clear cut choice for the number one spot. The debut album from Stefani Joanne Angelina Germanotta about the power of celebrity was an absolute sensation. Singles such as "Poker Face," "Paparazzi," and "Just Dance" have all hit number one on the singles chart and Lady Gaga was just nominated for a Grammy for Album of the Year.

Timberlake took four years to follow his sensational debut, Justified. But this album was worth the wait and became a hit even outside Timberlake's typical teenage audience, ultimately selling more than nine million copies. Co-written and co-produced by Timberlake and Timbaland, FutureSex/LoveSounds gave us Timberlake's first number one single, the infectious "SexyBack."

Stefani's solo debut is a serious departure from her work in No Doubt. But Love.Angel.Music.Baby. is a fantastic ode to the 1980s and, nine million copies later, made Stefani a potential heir to Madonna's throne atop pop music. Its biggest hit, "Hollaback Girl" hit number one of the U.S. singles chart and became the first digital download to sell one million copies.

Minogue had long been a star in her home country of Australia and in Europe, but with the release of this, her eighth album, she reached similar heights in the United States. Fever is a perfect dance pop album, and it's most well-known for giving us one of the most recognizable songs of the decade in "Can't Get You Outta My Head," which reached number one in 40 countries and became Minogue's first top-ten hit in the United States in 13 years.

The third studio album from Beyonce introduced us to the former Destiny's Child singer's alter-ego Sasha Fierce. It also gave us another of the most memorable singles of the decade in "Single Ladies (Put a Ring on It)," which was Beyonce's fifth solo number one hit and Rolling Stone's number one single of 2008, as well as the multiple Grammy-nominated "Halo."

The first of two entries on this Top 13, Confessions on a Dance Floor was hailed as a triumphant return to form for the Material Girl. The songs are all upbeat and blend together with no gaps so as to sound like a DJ's set. The album's first single, the ABBA-infused "Hung Up," earned a spot in the Guiness Book of World Records by hitting number one in 45 different countries.

Featuring three number one hits, Rihanna's third studio album was largely viewed by critics as the Barbadian singer's best work to date. Good Girl Gone Bad, by far Rihanna's most sexually suggestive release, was also a commercial success, selling nearly eight million copies worldwide. The album is best known for its Grammy-winning collaboration with Jay-Z, "Umbrella."

Stepping away from her teeny bopper image, Spears took a larger role in the album's writing and production. The result was her third straight number one album and more than nine million copies sold. Highlights include "I'm a Slave 4 U," which was written and produced by The Neptunes, and "I'm Not a Girl, Not Yet a Woman," which doubled as the theme song for the film Crossroads, which featured Spears in a starring role.

Unless you're just emerging from a decade-long coma, you know the lead single from Confessions. "Yeah!," featuring a crunk beat and vocals from Lil Jon and a verse by Ludacris, was number one in the United States for a record 12 weeks and pushed sales of the album worldwide to over 20 million. By far Usher's biggest commercial success, many of the album's songs are rumored to be about his breakup with Chili of TLC.

The second album from the first winner of American Idol, Breakaway remains Clarkson's best-selling album to date with over 13 million copies sold worldwide. The album won two Grammy Awards, including one for the its fantastic single, "Since U Been Gone," which helped move Clarkson beyond her initial American Idol-generated audience. Earlier this year, Pitchfork ranked the single 21st in its "Top 500 Tracks of the 2000s."

Featuring the uber-hits "Dirrty" and "Beautiful," Aguilera’s second album was her attempt to shed her "super-clean, cookie-cutter" image. Aguilera co-wrote 14 of the album's songs, which were mainly produced by Dr. Dre acolyte Scott Storch and Linda Perry of 4 Non Blondes fame. X-Tina's creative vision was a commercial success, selling more than 13 million copies worldwide.

Lavigne was credited with co-writing most of the songs on Let Go with the production team known as The Matrix, although there remains some question as to the extent of her role in creating the songs on this highly successful debut. Whoever wrote them, the public ate them up, especially chart-topping hits such as "Complicated" and "With You." Selling over 16 million copies worldwide, Let Go remains Lavigne's most successful album.

Madonna's second entry on this Top 13, Music, largely produced by French dance music composer and multi-instrumentalist Mirwais, sold an astounding four million copies in its first ten days in release, topping the charts in more than 20 countries. The album's terrific title track was Madonna's twelfth number one hit in the United States and made her just the second artist to top the charts in the 1980s, 1990s, and 2000s.