It depends on what you're looking for. If you are an absolute beginner, I would recommend the golden series- Harry Potter by JK Rowling. Needless to say, it has captivated youngsters and adults alike.
If you are into Victorian/Edwardian setting novels, I would recommend Pride and Prejudice or Sense and Sensibility by Jane Austen.
If you want a bit of thrill and adventure, we have Dan Brown's Robert Langdon series and his two standalone novels. Angels and Demons is the best of the lot.
If you want to go with young adult fiction, most people would start with The Fault in our Stars by John Green, though it is quite overrated. I would recommend Aristotle and Dante Discover the Secrets of the Universe by Alire Saenz, Eleanor and Park by Rainbow Rowell and The Perks of Being a Wallflower by Stephen Chobsky.