Most disappointing book relative to expectations?

What's the worst book you've ever read, discounting self published crap?

I bought my mom Jo Watson's Among Others half a decade ago for mother's day.

I didn't know much about the industry so I thought that it winning the Hugo meant it had to be at least of decent quality. It was so bad that she said it had to read it too

300 pages of the most pretentious precious child crap