The fact that the book is still being taught and discussed speaks to the number of people who like this book. The characters are contemporary in that we recognize the very same types of people today even though the book was written 30+ years ago. The language and situations are easy to understand, and we recognize people in our own experience in the novel.
I like the Outsiders a great deal. In many ways I think the tension and the conflict between the Socs and the greasers explored in the novel is timeless. Although I didn't grow up in the era described by S.E. Hinton, I could easily see the reflections of the conflict in my own world. For me, one of the hallmarks of great literature is when I can see myself and my world reflected in the work. There are elements of several of the characters that I see in myself; there are obstacles faced by these characters that I too have faced. As I grow older, I see this more and more.
A lot of people must like it since it continues to be published and read even now, so long after it was written.
I know that I, personally, liked it when I first read it as a teen. I really admired Ponyboy back in those days because he seemed like a very cool mix of intelligence and athleticism and toughness. I kind of wanted to be like that.
I still like it pretty well today. I think of it more now in terms of Pony overcoming a lot of pressure and I think about how it portrays teens -- it's more interesting to me for those reasons now. But I still like it.
At our school, we had to read it for English in year 9. I found it to be very enjoyable and entertaining and I could imagine it in real life. The book obviously had more detail than the movie but it was one of the best books I've read in a long time. I liked the book but the current year nines hate it!!!
I read it myself personally and I enjoyed it very much. I believed the characters were realistic and rational (for the time period that is). It's a tale of adventure and hardship but most importantly friendship and loyalty no matter what might happen. Many people still read it today and I know for a fact my old elementary school still makes the intermediate grades read it.