I found this list on another blog and I liked it. Bold are ones I’ve read and italics are ones that I’m reading/own and have started reading.
1) Harry Potter and the Sorcerer’s Stone by J.K. Rowling
2) Harry Potter and the Chamber of Secrets by J.K. Rowling
3) Harry Potter and the Prisoner of Azkaban by J.K. Rowling
4) Harry Potter and the Goblet of Fire by J.K. Rowling
5) Harry Potter and the Order of the Phoenix by J.K. Rowling
6) Harry Potter and the Half-Blood Prince by J.K. Rowling
7) Harry Potter and the Deathly Hallows by J.K. Rowling
8) The Hobbit by J.R.R. Tolkien
9) The Da Vinci Code by Dan Brown
10) 1984 by George Orwell
11) Pride and Prejudice by Jane Austen
12) The Catcher in the Rye by J.D. Salinger
13) To Kill a Mockingbird by Harper Lee
14) The Great Gatsby by F. Scott Fitzgerald
15) The Lord of the Rings by J.R.R. Tolkien
16) The Kite Runner by Khaled Hosseini
17) Jane Eyre by Charlotte Bronte
18) The Curious Incident of the Dog in the Night-Time by Mark Haddon
19) Life of Pi by Yann Martel
20) Animal Farm by George Orwell
21) Angels & Demons by Dan Brown
22) Brave New World by Aldous Huxley
23) Wuthering Heights by Emily Bronte
24) One Hundred Years of Solitude by Gabriel Garcia Marquez
25) Memoirs of a Geisha by Arthur Golden
26) The Time Traveler’s Wife by Audrey Niffenegger
27) The Odyssey by Homer
28) Catch-22 by Homer
29) Slaughterhouse-five by Kurt Vonnegut
30) Crime and Punishment by Fyodor Dostoyevsky
31) Fahrenheit 451 by Ray Bradbury
32) American Gods by Neil Gaiman
33) The Chronicles of Narnia by C.S. Lewis
34) The Hitchhiker’s Guide to the Galaxy by Douglas Adams
35) Lord of the Flies by William Golding
36) The Lovely Bones by Alice Sebold
37) Ender’s Game by Orson Scott Card
38) The Golden Compass by Philip Pullman
39) Good Omens: The Nice and Accurate Prophecies of Agnes Nutter, Witch by Neil Gaiman
40) Dune by Frank Herbert
41) Emma by Jane Austen
42) Frankenstein by Mary Wollstonecraft Shelley
43) The Adventures of Huckleberry Finn by Mark Twain
44) Anna Karenina by Leo Tolstoy
45) Jonathan Strange & Mr. Norrell by Susanna Clarke
46) Middlesex: A Novel by Jeffrey Eugenides
47) Wicked by Gregory Maguire
48) Lolita by Vladimir Nabokov
49) The Silmarillion by J.R.R. Tolkien
50) The Iliad by Homer
51) The Stranger by Albert Camus
52) Sense and Sensibility by Jane Austen
53) Great Expectations by Charles Dickens
54) The Handmaid’s Take by Margaret Atwood
55) On the Road by Jack Kerouac
56) Freakonomics by Steven D. Levitt
57) The Little Prince by Antoine de Saint Exupery
58) A Wrinkle in Time by Madeleine L’Engle
59) Neverwhere by Neil Gaiman
60) The Grapes of Wrath
61) Little Women by Louisa May Alcott
62) The Name of the Rose by Umberto Eco
63) The Scarlet Letter by Nathaniel Hawthorne
64) Moby Dick by Herman Melville
65) The Complete Works by William Shakespeare
66) Guns, Germs, and Steel by Jared Diamond
67) Me Talk Pretty One Day by David Sedaris
68) The Poisonwood Bible by Barbara Kingslover
69) Hamlet by William Shakespeare
70) Of Mice and Men by John Steinbeck
71) A Tale of Two Cities by Charles Dickens
72) The Alchemist by Paula Coelho
73) The Bell Jar by Sylvia Plath
74) The Picture of Dorian Gray by Oscar Wilde
75) The Elements of Style by William Strunk
76) Love in the Time of Cholera by Gabriel Garcia Marquez
77) The Subtle Knife by Philip Pullman
78) Atonement by Ian McEwan
79) The Brothers Karamazov by Fyodor Dostoevsky
80) The Secret Life of Bee by Sue Monk Kidd
81) Dracula by Bram Stoker
82) Heart of Darkness by Joseph Conrad
83) A Clockwork Orange by Anthony Burgess
84) Don Quixote by Miguel de Cervantes Saavedra
85) The Amber Spyglass by Philip Pullman
86) A Portrait of the Artist as a Young Man by James Joyce
87) The Unbearable Lightness of Being by Milan Kundera
88) Siddhartha by Hermann Hesse
89) Neuromancer by William Gibson
90) The Canterbury Tales by Geoffrey Chaucer
91) Persuasion by Jane Austen
92) Anansi Boys by Neil Gaiman
93) The Historian by Elizabeth Kostova
94) Angela’s Ashes by Frank McCourt
95) A Heartbreaking Work of Staggering Genius by Dave Eggers
96) Oh the Glory of It All by Sean Wilsey
97) Thank You, Jeeves by P.G. Wodehouse
98) The History Boys by Alan Bennett
99) Twilight by Stephanie Meyer
100) The Prince by Niccolo Machiavelli
A few additions of my own, original list from Be Naughty and Love It!