not much to look at

A person who is not very good looking, or not good looking at all. Can typically vary from 'Plain Jane' or 'Average Joe' to somebody who is extremely displeasing to the eye, or plain out ugly. Often quite boring to look at as well, and can be out right ignored as well.

'Not only does Amanda try too hard to be cute and dumb, but she's quite ugly and fat too. Really, she's not much to look at'.