I'm thinking of authors that have a distinct and strong voice. Some authors seem different in every book, but some always have the same voice. I don't find that to be a good or bad thing, just different. For me, Bukowski and Hesse have very strong voices, where all their works are essentially extensions of their thoughts. Curious what others think.
Augusten Burroughs comes to mind. It's really entertaining until it's not anymore. Authors like that, for me, have to be read sparingly, otherwise you get burned out.
I was thinking Hemingway when I wrote but pulled back because I think his voice can get lost in the stories. I haven't read a lot of him though. Mark Twain also comes to mind
Chuck Palahniuk has a pretty strong voice. Granted, a couple of his characters often say "jump to" to cut from one time frame to another. One is from Invisible Monsters, and I think he did it for another book, not sure. But either way, the crass and casual language of his is always nice. I particularly liked the voices for Snuff, Damned, and Fight Club, as the easy going language made it easy to stomach the volatility of each story's situations.
The first author that comes to mind is Carlos Ruiz Zafon. His diction is incredibly unique and his style is consistent across his books, even though the narrators' voices are distinct.