I am insanely guilty of this! Some have worked out, others haven't.
Twilight: Yep, I read this back in 2005 when it came out and the cover was what drew me in. I still think it's one of the better YA covers and has started a bit of a YA cover revolution.
Across the Universe: Haven't even touched it yet but the cover is beautiful.
Stolen by Lucy Christopher: I'm not sure why but I think this cover is just lovely. Its simplicity is what works.
The Unbecoming of Mara Dyer: This book was on everyone's list for interesting covers. Obviously, I am included!
Hush, Hush: I started to read this but couldn't get into it. I plan on trying again but this cover is just amazing!
Delirium: I love everything about this book, including the amazing cover!
Wither: I just grabbed this book one day without even looking at the description. The cover alone sold me.
Anna Dressed in Blood: The title, the cover, just everything works.
The Dark Divine: So pretty!
Hereafter: I am completely in love with this cover but couldn't get into the book. Maybe I'll pick it up again?