Half-way through the book: this is hilarious, can't stop laughing! 
 Two thirds into the story: gosh, John Green, please don't turn this into another sloppy drama. 
 20 pages before the end of the story: Thank you! They made it through the drama and it's goddamn funny again! Of course, you can't end a book like this one by hanging a cloud of depression over the reader. 
 Last 3 pages: OH MY! Speechless. 
 I realise this is a rather incoherent book review, but I haven't invented a way to describe such stories yet. Looking for Alaska has everything one would want: extremely funny jokes every other page, fascinating narration, smart thoughts to absorb, the evolution of a young protagonist (you can be a nerd and a bookworm and have fun with alcohol, cigarettes, executing amazing pranks at the same time), life and death questions, raising the eternal topic of forgiveness (can you forgive someone who hasn't asked to be forgiven?) and of course a mystery to solve. 
 The ONLY drawback is that, unfortunately, I managed to solve the so called mystery approximately 30 pages before the characters did. That was a bit disappointed. 
 Still, 4 out 5 stars for being able to provide a perfect mix of fun, drama and food for thought in 200 pages. Bravo, John Green.