Well, Random House (which just "reorganized"--there's an unfortunate amount of that going on in publishing these days) has this books=gifts campaign trying to get people to give books as holiday gifts. It's a good idea, but I think my title for the campaign is catchier.
Books, even hardcovers, remain a tremendous entertainment value. For 25 bucks, you can get a new DVD and spend two hours max being entertained. You can also get a used video game that probably wasn't any good in the first place (because the good ones command over 40 bucks used) but might give you a few hours of entertainment. Or you can buy a brand spankin' new hardcover book. Or two paperbacks! Possibly even 3 if you play your cards right, sale-wise.
And a book is a nice, thoughtful gift--even if the recipient doesn't like, or even never opens it, it shows that you were really thinking about them and who they are and what they might like.
Here's the only rule. When you give a book as a gift, you must never, never ask about it. If it gets read and enjoyed, you'll hear about it. If you hassle people about whether they're reading, your "gift" becomes burdensome, and fewer people will want to give or receive books as gifts. So hand over the book and then shut up.
Apart from my own oevre, which I of course recommend strongly, here are some books I think would make lovely gifts:
YA Novels: Someone, I can't remember who, described YA novels as "novels without all the bullshit." They tend to be quick, easy, entertaining reads, and many deal with interesting and deep issues without boring the hell out of you. Give these to teens or adults you love:
Charles deLint, The Blue Girl. It's hard to be the new girl in school. Especially when contact with semi-malevolent fairies turns you blue from head to toe and ghosts develop stalker-ish crushes on you.
Larry Doyle, I Love You, Beth Cooper. A really funny book about a dork's graduation night, it reads like a novelization of the funniest teen movie never made. Which it is. It started life as a movie treatment, became a novel, and is now becoming a movie again. If you like those Judd Apatow "raunchy, but with a big heart" comedies, you'll love this.
China Mieville, Un Lun Dun--Don't you hate it when you discover a parallel city below your own, and your best friend becomes the chosen one who has to save the place, but then she falls down on the job and you have to do it even though you don't fulfill the ancient prophecy? Me too!
Neil Gaiman--Graveyard Book. One of the best things I've ever read. Definitely a classic of children's literature. Give it to kids, and they'll pass it on to their own kids.
Horror/Fantasy Type of stuff. Yeah, a lot of the YA books I recommended fell into that category too. So sue me.
Charlie Huston--The Joe Pitt Casebooks, starting with Already Dead. Under most people's radar, Charlie Huston is creating the noir Harry Potter--an engrossing, fully-realized world and a story that starts small and keeps growing bigger and bigger. If you like detective stories and you prefer your vampires thirsty and brutal rather than wan and romantic, these books are for you.
Dan Simmons, The Terror--A 19th-century Artcic expedition winds up with two ships stuck in the ice. Gory complications ensue.
Liz Williams, Snake Agent. It's a fantasy! It's a horror novel! It's a police procedural! It's a buddy comedy! It's all of the above!
Non Fiction:
David Hadju, The Ten-Cent Plague-- it's about the anti-comic book hysteria of the 50's, but is pretty enlightening about how any of these "blame our real or imagined problems on a pop culture scapegoat" phenomena get started.
Tom Vanderbilt, Traffic--If you drive in the United States, you need to read this book.
Books by friends of mine that are really good even though I understand my recommendation may be kinda suspect:
Dana Reinhardt, How to Build a House--a great YA novel about a girl who volunteers to build a house in a disaster-ridden community and ends up coming to terms with how her own home has been destroyed.
Tasha Alexander, And Only To Deceive--first in a series of mysteries set in Victorian England. I enjoyed it immensely--the whole "is the dead husband really who he appeared to be?" plot was very engaging, and the main character really appeared to be a Victorian woman rather than a modern woman dropped into a Victorian setting. Great for mystery lovers, history buffs, and Anglophiles.
Lauren Groff, The Monsters of Templeton--Can you go home again, especially when you have a difficult relationship with your mom, you've screwed up your life royally, there's a mystery at the heart of your identity, and there's a monster in the lake in the middle of town? Read and find out!