75%: complete, proofread by one user, and standard.
50%: not proofread or standardised.
25%: incomplete, not proofread, or nonstandard.
Missing, please add
Copyright problems - beware
The following are the public-domain members of various lists of important books, along with their current status on Wikisource. If you can add or improve any of these, that would be a big help! If a book is included in one list, it isn't included in subsequent lists.
Modern Library's list of the 100 best non-fiction works of the 20th century 
- From http://www.randomhouse.com/modernlibrary/100bestnonfiction.html
- ↑ I'm not sure which autobiography is referred to here. Gutenberg lists Chapters from My Autobiography by Mark Twain (no date given, edited by "N. A. R."), Mark Twain's burlesque autobiography -- First romance. (1871), and Mark Twain's Autobiography, Volume 1 (1924, fragmentary, with an introduction by Albert Bigelow Paine). None of these are the same. Amazon offers The Autobiography of Mark Twain (Perennial Classics) which it claims is under copyright. This needs an expert.
- ↑ Many of the essays here were also included in The Sacred Wood, published in 1920. These include Tradition and the Individual Talent (1917), “Rhetoric” and Poetic Drama (1919), Euripides and Professor Murray (1918), Notes on the Blank Verse of Christopher Marlowe (1918), Hamlet and His Problems (1919), Ben Jonson (1919), Philip Massinger (1920), William Blake (1920), and Swinburne as Poet (1920). Other essays in this collection known to be in the public domain are The Metaphysical Poets (1921), Andrew Marvell (1921), and John Dryden (1922), but I can't find any online sources for these. All other essays in Selected Essays were first published after 1922, and are thus still under copyright.
Modern Library's list of the 100 best novels of the 20th century 
- From http://www.randomhouse.com/modernlibrary/100bestnovels.html
Radcliffe's list of the 100 best novels of the 20th century 
- From http://www.randomhouse.com/modernlibrary/100rivallist.html
Literary Review of Canada's list of Canada's Most Important Books 
- From http://lrc.reviewcanada.ca/index.php?page=1---10
The Hundred Most Important Science Books of the Second Millennium 
- From http://www.geocities.com/millscibooks/index.html
Other lists