Here is a list that you may enjoy reading. Even though some may be classed as children, i found them enjoyable reading just the same.
Books/Authors
A wrinkle in Time - Madeline L'engle
The Dark is Rising - Susan Cooper
Up the line - Robert Silverberg
Raising the Stones - Sherri S Tepper
The wizard of earthsea - Ursla Leguin
The Crystal Cave - Mary Stewart
Most of these will be a quick read and have a few books in each series. If you havent read them, try them out)