The Modern Library, lists of 100 best fiction and 100 best non-fiction books. Two version of each list, one chosen by a panel of critics, the other voted for by readers.
The BBC's Big Read, 100 novels voted for by BBC audiences.
Time Magazine's all-time 100 novels published between 1923 and the present, chosen by Time's critics.
Top 100 books of all time, via the Guardian, 'as determined from a vote by 100 noted writers from 54 countries'.
The top 100 books, via the Telegraph - no explanation of how they were chosen.
Another Telegraph one, the 110 books that make up the perfect library.
This one is interesting: the most downloaded books from Project Gutenberg.
Waterstones' top 100 books of the twentieth century.
And in response to the male-centricity of most of the above, the top 100 books by women, although I can't find the link to the original.