Read on a subject you are interested in.
If you like horses, read about horses. If you like baseball, read about baseball.
For specific book recommendations, it depends on the person's age and interests.
For little kids, Dr. Seuss, the Hungry Little Caterpillar, the Mouse, the Bear and the Red Ripe Strawberry.
For older kids and teens, Harry Potter, The Lightening Thief, The Hunger Games, My Friend Flicka, The Secret Garden, White Fang.
Romantic: Good in Bed, In Her Shoes, Jemina J,, Agnes and the Hitman
Vampire Erotic-JR Ward and Kresley Cole
Action/Danger: Dark Rivers of the Heart, Intensity, Don't Say a Word, The Killing Floor, Tell No One
Comedy: Sick Puppy, The Custom Van (Dirty)