"Poetical Works of Lord Byron, with Life", Gall & Inglis Landscape Series of Poets. Similar, but not identical to the one
pictured here. (The flower arrangement on mine is different.) Undated, but somewhere between 1860 - 1880's. I cherish it not because of what it is, but rather where I was and who I was with when I purchased it.
A small-format printing of Black Beauty by Henry Altemus Company's Vademecum Series, from 1900. This is a book that has just always been around in my life, as far back as I can remember. Small miracle that it's never gotten lost in any of my moves, and I like to think it's with me for a reason.
My signed 20th anniversary limited edition of Bentley Little's The Mailman. Because it's the only such thing I have.