For the "clean" covers I could find (free of logo/scan bar etc.) See Cover Art Gallery. For pencils and inks of covers, see Cover Roughs.
Batgirl
Batgirl (third series)
Batman: Battle for the Cowl
Batman Chronicles
Batman Family
Batman: Gotham Knights
Batman: Huntress/Spoiler Blunt Trauma
Batman: The Widening Gyre
Detective Comics
Gotham Underground
Red Robin
Robin
Robin/Spoiler Special
Showcase '95
Teen Titans (Second Series)
Teen Titans (third series)
The Web
War Drums and War Games
World's Finest
Young Justice