Wesley Wyndham-Pryce, the mostly-incompetent Watcher from Buffy, joined the cast of Angel on episode 10 of the first season after Angel's former sidekick Doyle died. After Graduation on Buffy, Wesley had been fired from the Watchers Council. Over the summer, he had learned to fight and had become a "Rogue Demon Hunter," travelling the world on his motorcycle, hunting demons.
Wesley was soon hired by Angel Investigations and became their resident "research guy" and a good friend to Angel and Cordelia (and later to Gunn and Fred). Wesley is perhaps best known for two things: Mistranslating prophecies and receiving at least one major injury each season.
As far as injuries go, the count is currently at 3 major injuries, and several minor ones. In season one, Wesley had a cross jammed into his throat, was tortured by Faith, his former slayer, and was hospitalized after the Angel Investigations office was blown up. In season 2, the fun continued with Wes being shot in the stomach trying to protect Gunn. Season 3 was a more severe year for Wesley. Early on he became posessed, but that was nothing compared to what would happen later. Wesley had his throat slit after kidnapping Angel's son, after which Angel tried to suffocate him with a pillow. In season 4, Wesley wasn't injured as much physically as he was emotionally, but he did receive a few nice beatings and a bullet through the hand.
In the "Mistranslated Prophecies" department, there was the Shanshu, which Wesley thought stated that Angel would die when it actually said that he would become human. Whoops. But even more important was the prophecy that "The Father Will Kill the Son," regarding Angel and his newborn, Connor. That one turned out to be fake, but led to Wesley's rapid character development in late season 3 and season 4.
One other important thing about Wesley was how quickly, yet believably, his character changed from geeky research guy to broody kickass outsider. Wesley's kidnapping of Connor (for his good), seduction by Lilah, and subsequent descent into dark Wes made for some of the best moments in the series.
Wesley had always been a character who believes that "the needs of the many outweigh the needs of the few." On Buffy, he was ready to allow Willow to be killed in order to save the hundreds or thousands who would be killed by the mayor. Wesley's main flaw is that he acts too quickly. He'll make decisions without others (such as sending Faith back to the Watcher's Council) and without thinking out the consequences (bringing back Angelus to defeat the Beast). These traits were always in the character but were hidden by his goofiness. When he was abandoned by his friends, it made sense that his worst traits would be pushed to the forefront.
About the Site
WA was created in March 2002, sometime after the episode "Sleep Tight" aired. It was created because, at the time, there weren't that many Wesley sites out there. Turns out a whole bunch of them sprang up around that time to show appreciation for the guy. That tends to happen when a character is critically injured.