I don't often read YA novels, and I even less frequently blog about and recommend them. Natalie Babbitt, however, was one of my favorite authors growing up, and I occasionally enjoy re-reading her short YA novels just for fun, and I have yet to tire of them. Both Tuck Everlasting and The Search for Delicious can be read in one sitting, and they are decidedly of a different era in YA fiction, before it was called "YA fiction." They lack the genre-y quality of later popular YA novels, but still somehow manage to gracefully skim the surface of fantasy or sci-fi, much like The Giver or A Wrinkle in Time.
Tuck Everlasting is the story of a girl who encounters a family who have attained immortality by drinking from a spring. That is only the basic premise, because it is such a simultaneously rich and spare little book, and is quite honestly one of the most romantic books I've ever read. I can't speak to the film adaptation starring Rory Gilmore because that would ruin the perfect vision of the characters and the world of Treegap that I have in my mind.
The Search for Delicious is a bit more traditionally whimsical and fantasy-oriented, with a young boy roaming his kingdom with the express purpose of polling its citizens for the definition of "delicious" for a royal dictionary. Profundity ensues, plus there are mermaids.