Why she's on the list:
Sorry, Whitney. Mariah trumps you once again. Carey would work better in Rock Band than Guitar Hero, with her earlier R&B hits a more natural fit for the game's instrumentation than her later, more hip-hop oriented work. Despite her well-publicized breakdown, Carey is scarily popular, with lifetime record sales certified at almost 120 million.
Why she may not be in the games:
Like some of the other pop stars on this list, she's not the most obvious choice for full-band games, and her laughably gratuitous melisma and extreme range probably make her the Mike Tyson of the karaoke games she appears in. Still, tell me you wouldn't love to play that Tom Tom Club bass hook sampled on "Fantasy," or slur out ODB's famous rap.