There is a fun author that I haven't heard anyone else talk about for a very long time named John Bellairs. I remember reading his books when I was younger and loved them. They are kind of a mix of fantasy, detective and adventure. Be sure to check out The House with a Clock in its Walls, The Figure in the Shadows or The Letter, the Witch and the Ring. Another option would be the Sherlock Holmes books but that may be a bit advanced. Good luck!!
Old but brilliant I hope: Treasure Island, Robinson Crusoe and Lord of the flies.
I think girl with the dragon tattoo series may not be a good idea for a parent to introduce their teenager to, he will get to them eventually on his own. Am I getting too old and prudish I wonder? I prefer the Henning Mankell books.
'The Catcher in the rye' by Salinger, he might be a bit young for it, but it's pretty engaging and the conscious flow style of writing is quite easy to follow. Quite depressing but also empowering.
Unless they're at an advanced level, my student's still enjoy some graded readers. He might enjoy the Sherlock Holmes graded level series. Seems most most Swiss do.
Yes, H.P. Lovecraft is absolutely great - I should read some of his' again. If the boy is into sci-fi or horror, he should read him to know where all the TV trash we have today originated from - and how good it actually can be.
OK after doing a lot of research I finally ordered one of the wimpy-kid diaries and read it - hilarious. I only hope the 13-year-old will enjoy it too. And for the future I got lots of great suggestions - thank you all. I will certainly get one or the other of the books some of you suggested.