Hi, this is my first post on these forums, but I'm really into literature and I guess given my username it's appropriate I post here first. I must say I'm quite impressed by your choices so far, maybe a little fantasy-centric, but hey at least you're distinguishing your JK Rowlings and Terry Pratchetts from your Stephanie Meyers
So... This will be a long list and no doubt I'll forget some stuff but here we go:
Discworld series, Terry Pratchett
Harry Potter series, JK Rowling
Swallows and Amazons series, Arthur Ransome
The Master and Margarita, Mikhail Bulgakov
A Dead Man's Memoir/Black Snow, Mikhail Bulgakov (there are two different titles of the English version, personally I prefer A Dead Man's Memoir as it is, well, more descriptive

plus Black Snow refers to the title of the protagonist's play, quite different from the book as a whole... but yeah I think I got sidetracked there)
A Dog's Heart, Mikhail Bulgakov
The Castle, Franz Kafka
The Trial, Franz Kafka
Amerika, Franz Kafka
The Great Gatsby, F Scott Fitzgerald
Tender Is the Night, F Scott Fitzgerald
East of Eden, John Steinbeck
The Grapes of Wrath, John Steinbeck
The Fall, Albert Camus
The Stranger/Outsider, Albert Camus
No Country for Old Men, Cormac McCarthy
Howard's End, EM Forster
Scoop, Evelyn Waugh
The Bell Jar, Sylvia Plath
The Catcher in the Rye, JD Salinger
There that's my twenty, in an overly long post that still manages to miss out some classics
