These are a few books that have inspired me and changed the way I think about the world (and are just lots of fun).
Blood of Elves (Witcher Series, Book 3) - Andrzej Sapkowski
The quote I pulled from the book is similar to Arthur C. Clarke's Third Law, which states “Any sufficiently advanced technology is indistinguishable from magic.” Both get at the same point, which is that things are only frightening as long as you remain ignorant of them, and anything can be made not frightening by devoting yourself to learning about it. Vesemir was specifically talking about monsters, and Clarke was talking about science and technology, but the same exact principle can and should be applied to everything in life. Most prejudices (e.g. racism, homophobia, etc.) are based on fear, and fear is based on ignorance, so simply by learning about the people or things that you're prejudiced against you can often remove that prejudice from your life.
"When you know about something it stops being a nightmare. When you know how to fight something, it stops being so threatening." - Vesemir
Redwall (Redwall Series, Book 1) - Brian Jacques
I read the first Redwall book when I was in third grade and immediately fell in love with it. The plots aren't complex or twisting. Good triumphs over evil. The good guys and bad guys are always clearly defined and you never have to guess at a character's motivations. They're well-written, enjoyable, simple tales that make you feel good at the end of the day. Also, all of the characters are anthropomorphic animals, and that's just fun.
“Even the strongest and bravest must sometimes weep. It shows they have a great heart, one that can feel compassion for others.” - Cornflower
The Innocents Abroad - Mark Twain
It's difficult to not like everything that Mark Twain ever wrote, but this combination of autobiographical storytelling and satirical send-ups of the over-the-top nature of mid-19th century travel books makes for a raucously good time. Impressively, the satire holds up 150 years later because modern day travel blogs on the internet are equally as absurd and over the top of the travel books written in the mid-19th century. There is a particularly memorable section in the book where Twain and his travel companion antagonize a museum tour guide for showing them a "derelict" mummy instead of a fresh one that never fails to leave me in stitches. It's a thoroughly recommendable read for anyone, but especially for anyone who has done some amount of traveling abroad.
“The gentle reader will never, never know what a consummate ass he can become until he goes abroad. I speak now, of course, in the supposition that the gentle reader has not been abroad, and therefore is not already a consummate ass. If the case be otherwise, I beg his pardon and extend to him the cordial hand of fellowship and call him brother. I shall always delight to meet an ass after my own heart when I have finished my travels.”