I haven't been a close follower of Kate Beaton's online comics, although I love them whenever I happen across a link. Now there's a collection of a whole bunch of them.
Beaton's a historian so a lot of her comics are about historical figures or times, but some are based on books or are just for the hell of it. They're very, very funny even if you don't necessarily know what the source material is. What's best, though, is Beaton's artwork--skillful, beautifully rendered, and funny in its own right. Her ability to convey emotion (especially fury or disgust) through expression reminds me a bit of Nicole Hollander's Sylvia comics, but with a swifter, cleaner line.
This is a good big collection. I went to bed early last night with the book, half a candy bar, and a can of Coke, and was deliriously happy.