An example of this is Amazon's top 10 list. The website's list is created solely on what books it has sold in that genre to date. Many of these informational venues are not based on any sort of research, but only book sales and fan votes to that specific site. Example two, Goodreads.com has a list which is complied only of the votes of that sites viewers; again, no research.
Luckily, I have done my research and based on overall popularity and book sales, and have thus found what I feel is the best and most well-rounded "top 10" list available, thus far in the century.
4. Lord of the Rings: Although published between 1954-1955, The Lord of the Rings has enjoyed an enduring fan following, as well as a new revival in fans due to The Lord of the Rings trilogy of movies directed by Peter Jackson. These books have had many influences on popular culture, including the language of Elvish, an expansion in the genre of fantasy fiction and the inspiration of filmmakers such as George Lucas. 'LOTR' fans have been known to get tattoos inspired by the series as well as create fan art. Over the years, sales of these books have topped 150 million. The Lord of the Rings trilogy of movies reached a box office revenue close to $3 billion.
10. Sookie Stackhouse: Charlaine Harris’ Sookie Stackhouse novels haven’t quite reached a Twilight frenzy, but the books that started True Blood have a rabid collection of fans, commonly referred to as 'Fangbangers.' The Fangbangers often descend upon the towns of Shreveport and Monroe, Louisiana in search of the fictional Bon Temps, Louisiana that True Blood is set in. These novels went on to create the True Blood drama series that has enjoyed fandom and critical acclaim, including a Golden Globe and Emmy. In its third season, True Blood is now HBO’s most watched series since The Sopranos."
This information is courtesy of Online Colleges.
Pictures via Google Search.