Those of you who love Robin McKinley are no doubt already acquainted with The Blue Sword, as it is one of her very early works. However, I had the opportunity to discover it for the first time this past December, and fell completely in love.
This high-adventure tale has all the elements neccessary for a really good story: swordfights, kidnapping, danger, excitement, romance, and compelling characters. I loved it so much, I bought a copy online before I'd even finished reading the library copy. Highly recommended.