Douglas Adams would have been 61 today.
So, with that in mind, I'm going to point you back to my review of Meg Rosoff's There is No Dog—the only book I've read in a long, long time that came anywhere close to giving me the same feeling as a Douglas Adams book:
It wasn't just the tone that reminded me of Douglas Adams. It was the warmth—it was how Meg Rosoff was able to poke fun at (and sometimes skewer) humankind (and our mythology), while also conveying a sense of never-ending affection, wonder, and empathy. There's a sense of hope, too, but it's a realist's sort of hope—one that takes the past into account—so while there are brief, perfect moments of beauty, everything is tempered with a cheerful sort of pessimism.