Well, I don't really have any unique gems, though my whole collection consists of decent stuff
>Jethro Tull's Thick As A Brick - first british press, original newspaper-sleeve
>Crimson's In The Court Of the Crimson King and Lark's Tounges in Aspic - first british press
>Genesis' The Lamb Lies Down on Broadway, Trick Of The Tail - first british press
>Talk Talk's Spirit of Eden - fbp
>Floyd's The Wall and Animals - fbp
>Cohen's Songs of Love and Hate or Songs of Leoanrd Cohen - first american press
just to name my personal favourites