Wesley Crusher is a close second to Neelix for the most hated character in Star Trek. The son of Jack and Beverly Crusher, Wesley is a child prodigy with an intuitive understanding of many Federation technologies.
Gross mishandling of the character by the writers of Star Trek: The Next Generation turned him into an egotistical nerd, and repeated plots in which he either saved the ship with his science project or nearly destroyed it with the same quickly got old with fans. Later writers tried to correct these problems, but their efforts were too little, too late.
Going My Way?
Early in TNG, an alien called the Traveler befriended Wesley, impressed with the boy's great mental prowess. This alien turned out to be another super-being who could affect reality with his thoughts. In TNG's final season, he took Wesley with him to a higher plane of existence. Given the Traveler's appearance and the intense hatred of Wesley, fans like to think there were other reasons behind the relationship.
The Scene We Never Got to See
In the original script for Yesterday's Enterprise, Wesley was supposed to be decapitated in the battle.
While he was on the show, Wil Wheaton was largely unaware of fan opinion towards the character he played. In later years, he became one of the many critics on the character of Wesley Crusher. He includes several criticisms of his character here: