the puzzle is a great idea! kinda pricey but i'm sure my fiancé would LOVE something like that +REP
another "last-minute" gift idea is from my
secret-box-of-cheap-ass-gifts-that-will-make-her-go-awwww.. in a hand written note tell her how much you love her, how much she means to you, how much you appreciate her, and how you can't begin to thank her for all she does for you. mount the note on a colored/textured splash page then into a picture frame: roses, candy, dinner -- ta'daaa
make sure you don't have to go to work or go to school early the following morning, if you know what i mean