I gave this to one son when he was about 18, along with a pretty much complete set of Discworld: http://www.terrypratchettbooks.com/discworld-reading-order/. These were collected over many years, so a bit of a wrench. The best of which might be: "Wyrd Sisters" (Shakespeare), or "The Truth" (Newspapers). He can make fun of pretty much anything, while still showing it great affection.

Neil Gaiman's "The Graveyard Book" is a great book for reading to younger kids. Weird, creepy, but strangely uplifting, even if it does begin with a triple murder. I can't remember which kid took that.

I bought Robert Silverberg's "Nightwings" in the 80s and read it several times. I was going to give away but couldn't find it, so I had to buy a new copy and read it again first. This seems to anticipate a lot that followed, from genetic modification to drastic climate change, but it is essentially about a character trying to cope in a mad world.

I recently read the graphic novel version of Graveyard Book. Would highly recommend that as well, it is quite well done.

I also give this book as a gift often. It started when I'd lend it out and never get it back, which, on reflection, I found I was actually fine with. So I found a UK 1st Edition, signed by both authors, which I'm never lending to anyone, and buy whatever copy is to hand for people as I feel moved to.

I've also done this a couple times with Joe Haldeman's The Forever War.