My own preferences are strongly English first, and then Australian, and then pickings from the rest of the world, including the US.
Looking through the posts here it seems similar for the Americans - English first, and then the US, then the rest.
I’ve browsed The Western Canon by US critic Harold Bloom (a survey of the “greatest” literature) and he has a similar approach.
While I’m here then, some of my own favourites.
Australian
My Brother Jack - George Meredith. Considered to be “The Great Australian Novel”, apart from Patrick White’s more literary efforts. Highly recommended!
The Road from Coorain - Jill Ker Conway
The Seed’s Inheritance - Colin Thiele
(btw, the major Australian author is considered to be Nobel prize winner Patrick White, but I haven’t yet read anything of his. He has a reputation for being “heavy”)
Others
A Portrait of the Artist…, Dubliners - James Joyce
The Loved One - Evelyn Waugh
The Lord of the Rings - Tolkien
The Hunt for Red October - Tom Clancy.
Kidnapped, Treasure Island and short stories. Robert Louis Stevenson.
The Power and the Glory Grahame Green
not Dickens. I’m a slow reader, and his books are just too long for me
Catch-22 Joseph Heller
Mark Twain - by reputation, I’m afraid, but every quip and quote of his impresses to me.