For many seasons, Rupert Giles was the father figure to many of the Scooby Gang, including the Slayer herself. While this may have meant that he was often the butt of everyone's jokes, it became clear that Buffy Summers and her friends truly respected Giles, and loved him deeply.
Indeed, although Giles was merely Buffy's Watcher for the majority of his time on the show, he was also one of the most heroic Watchers that had ever lived. Despite this, Giles was by no means perfect, and some of his personality and actions made the character worse over time.
Hiding His Past From The Scooby Gang
When fans first met Giles, he appeared to be a fairly stuffy English librarian working in an American high school. However, they were thrown for a loop when it was revealed that Giles not only knew Buffy, but that he also knew about her Slayer status.
As if this wasn't surprising enough, it was revealed that Giles had quite a shady past. What was worse was that he had hidden it from the Scoobies. They had trusted him with their lives on a regular basis and Giles couldn't even be honest with them.
Hanging Out With The Scooby Gang
Because Giles was such a popular character, and because the show had always had Giles around, fans simply accepted the fact that Giles spent a lot of his time with the Scoobies. However, if one thinks about it, the amount of time Giles spends with the Scooby Gang is weird.
When Giles first met Buffy, Xander and Willow, he was a member of staff and they were all underage students. Yes, the necessity of their situation dictated that they spend a lot of time together but really, Giles should have known better to put himself in that position constantly.
Betraying Buffy
For someone who claimed to love Buffy like a daughter, and who always apparently had her best interests at heart, Giles sure made a habit of betraying Buffy while her back was turned. The first time was hiding the fact that Buffy would die at the hands of the Master.
Believe it or not, that wasn't the worst thing Giles would do. In Season 3, he deliberately weakened Buffy on the orders of the Watchers Council, which almost got her killed. Then, in Season 7, he plotted to take out Buffy's best chance at training the Potentials: Spike.
His Hatred Of Spike
With the definite exception of Xander, Giles was probably the one member of the Scoobies who hated Spike the most. While his hatred was understandable, it became a little bit old, bordering on prejudiced. Sure Spike was a vampire, but he made strides to being good.
In Season 5, although Spike was still vile and soulless, he protected Dawn with his life. In the following season, Spike helped the Scoobies even after Buffy's death. And in Season 7, Spike had his soul back meaning he could be properly good, and yet Giles still hated him.
He Always Left Buffy
For the first three seasons of Buffy The Vampire Slayer, Giles stuck with Buffy and always helped her out, whether it was through research, or simply an encouraging hand on her shoulder. However, in the seasons that followed, Giles seemed to be constantly abandoning the Slayer.
It was understandable that Giles wanted to wean Buffy off of him, especially as he wouldn't be around forever, but he could have handled it better. In Season 6, for example, he left Buffy when she was extremely vulnerable and emotionally raw.
His Lack Of A Social Life
In the early seasons of Buffy, Giles entered into a tentative relationship with Jenny Calendar. This relationship not only gave Giles more depth outside of being Buffy's Watcher, but it was also just utterly adorable to watch.
However, after Jenny died at the hands of Angelus, Giles never really got another chance to date, or form any other means of a social life. His main storylines were his job as a Watcher and his job as the Magic Shop owner. It would have been fun to see Giles form another relationship.
His Aversion To Technology
Giles's reluctance to bow down to technology was mostly played for laughs in the show and, to be fair, it was quite funny. However, even in Season 1, technology was developing fast and Giles was obviously falling behind.
However, Giles's reliance on his old books and texts were becoming slowly obsolete. Surely a good Watcher needs to keep up with the change of time to ensure that their Slayer survives. Giles was many things on the series, but a technical wizard he was not.
His Increasing Irrelevance
First of all, Giles was one of the best characters to come out of Buffy The Vampire Slayer. For the first three seasons Giles was instrumental in helping the Scooby Gang prevent the end of the world on multiple occasions.
However, as the show went on, Giles became less and less relevant. This could have been fixed by giving him a social life, but the simple fact was that Buffy needed him less. The series tried to make him necessary for a while, but eventually Giles left the show in Season 6, much to everyone's dismay.
Getting Knocked Out
Any proper Buffy fan will know that there was a running joke throughout the series concerning Giles's seemingly endless ability to get knocked out very frequently. Presumably it started out as a coincidence but then the show ran with it as a sort of Easter egg.
However, within the narrative, this wasn't exactly a great trait for a Watcher to possess. Giles was basically responsible for looking after and training the Slayer, which meant he should have had some experience of the supernatural, enough to prevent him from sleeping on the job constantly.
Treating Xander Differently
The Scooby Gang are basically like one big, massive family. Many of the either had emotionally distant parents, or wonderful, loving moms who died way too soon (Joyce Summers, you will always be missed). Therefore, it stood to reason that Giles was seen as a father figure to many.
While Giles obviously cared for Buffy the most, as that was his job, he also loved Willow as well, as the two were very similar. When it came to Xander, though, although Giles still cared about him, it was obvious that it wasn't as much as the other two.