The Magus is considered by some to be one of the top 100 books of the last century. I'm inclined to agree. This is my favorite "Desert Island" choice for a novel.

One can read Fowles' books repeatedly and still find numerous surprises you missed in the previous read.

The Magus is mystical, psychoanalytical, has great prose and last but certainly not least...is a gripping story. Don't miss this one!

Oh and grab the French Lieutenant's Woman as a great follow-up. The film adaptation certainly did the novel no justice as all, as usual.