“Novella” is a tough word because it sometimes implies a lack of… bigness. But here are some short books that I’ve been influenced by:
The Revisionist, by Miranda Mellis
A beautiful and fractured diorama of the future.
The Horla, by Guy De Maupassant
Three versions of a similar story: Man goes mad. Lucid and terrifying.
EVER, by Blake Butler
This book contains something new.
The Immoralist, by André Gide
Sorrowful and difficult.
Tracer, by Frederick Barthelme
Oh, boy. This book is funny and gorgeous. I think Barthelme really paints with light here.
Light Boxes, by Shane Jones
An exciting new myth.
Ken Baumann lives in Los Angeles, California. He edits the online literary journal No Posit and co-edits the print literary journal No Colony. He’s a founding member of BRAIN, an artist collective. His first novel, Interim, is currently running, looking for someone to bite. Find him HERE.
JOHN MADERA—Writer, Editor, Publisher 
Adding:
Log of the S.S. The Mrs Unguentine by Stanley Crawford
-One of the most beautiful stories I’ve read.
In Watermelon Sugar by Richard Brautigan
-Ditto. This book made me feel, entirely.
Waste by Eugene Marten
-A piece that really defines impeccable creation of ‘mood’ within story.