1984 is good, but I preferred Animal Farm of George Orwell's books. Also try Stephen King's The Dark Tower (It's not horror, more fantasy). I'm a classics fan, so I'll mostly be reading those, but my favorite contemporary authors (Other than Rowling, as you already read her most amazing books) are Stephen King (As mentioned above, even though I haven't read any of his horror yet. I know right? So weird), Brandon Sanderson (Try Mistborn, a high fantasy trilogy), Neil Gaiman (Stardust and Coraline are both really good if you need stand-alones). Also of high fantasy, read The Lightbringer series (Brent Weeks). The 5th book is still in the making though, so not sure if you want to start it yet.
Of the classics, which I love, Gone with the Wind is one of my favorites. Read The Catcher in the Rye too. Of other recommendations, there is The Handmaid's Tale, an Orwellian based novel. If you want satire, try The Princess Bride. If you've seen the movie, you've only read a tiny bit of the plot, as the book revolves around the author talking about himself, and mixes real life people/events/places with fictional ones. Really mind boggling.
If you have anything more specific (genres/time period) I could recommend more, right now I'm just suggesting anything popping into my head. Hopefully this helps!
