Alternative Character Interpretation: Happened a lot in Egypt; each city and area seemed to have their own take on the Egyptian religion, so as a result there are several sun gods and many other gods whose jobs and areas of expertise overlap.
Also, over time as different cults would be influential in the capitol, various gods would be honored or vilified.
Set in particular is a rather contentious god, thanks to the complicated history in regards to how Egyptians perceived him. Was he a callous tyrant, or a defender of Ra? Did he kill Osiris out of jealousy, or because he slept with Nepthys?
Big-Lipped Alligator Moment: The Egyptians themselves largely had this reaction to Akhenaten's experiment with Atenist monotheism and its associated artistic innovations. Research suggests Akhenaten had good reason for his decisions (beyond personal piety) rooted in the social and political conditions of his empire, that the Eighteenth Dynasty had started to raise Aten's profile before Akhenaten took the throne (his father, Amenhotep III, had made a few dedications to the previously-minor god) and that his reforms had some lasting impact (mostly to do with art, but the experiment also left some nasty political/dynastic consequences that led to the end of the Eighteenth Dynasty). However, at the time Egyptians appear to have felt that this new religion came from nowhere, was weird, and then left without leaving a significant trace.
Complete Monster: Apep, more widely known in the West by his Greek name, Apophis, was the Egyptian god of chaos, darkness, and destruction. Residing in the Underworld, Apophis took the form of a colossal snake, and every night, would attempt to devour the sun god Ra, as he made his way through the land of the dead, hoping to leave the world without light or life. During the day, while Ra was in the sky, Apophis would feed on those dead souls who were not properly protected against him, leading to their complete obliteration. His motives for doing so were that, as a primordial being associated with the dark, he hated the fact that there was a sun, or life on earth, and aimed to go back to the way things used to be. He was also the leader of armies of demons, and sought to subvert mortal confederates into aiding his nihilistic agenda. Reviled by all the other deities, including Set (who eventually took on the role of God of Evil), and universally loathed in Egypt, Apophis was the only god to have the distinction of never being prayed to. Instead, temples and ceremonies were set up to pray against him.
Anubis, in more modern times. For the common layman he may be the only Egyptian god they can name. Even though, while he was always among the major gods in ancient Egypt, he was by no means the most widely worshiped. Additionally, Anubis is the Greek name - his Egyptian name is Anapa or Anpu.
Bastet was a relatively minor goddess back in the day, but she's very popular today thanks to the Furry Fandom and the internet's love for cats.
For a lot of nerds/geeks with a passing interest in Egyptian mythology, Thoth is popular mostly because he's a Badass Bookworm.
Isis is this for the Westerns. Being the only Egyptian deities to escape relatively unharmed from Hellenization, has her own Greek-Roman temples, Greek names in her honor (Isidoros and Isidora) AND being the inspiration for Virgin Mary is a testament of that. While not any means a minor characters, she appears and her role in the overall mythology is significantly less than Osiris, Anubis and Set.
Evil Is Cool: This is probably the reason why Set is one of the most popular gods in pop-culture today.
Foe Yay: In the original version of the myth, Set asserts his dominance over Horus by seducing him, getting him drunk, and then rapinghim. Egyptian attitudes to this story varied wildly, some using it as a justification for homophobia (since clearly only a Depraved Homosexual would do such a thing), and others telling a different version where Horus is totally not gayfrom the experience because he actually received Set's semen in his hands and not in his... you know.
And then there's the addition that Horus put some of his own semen on some of Set's lettuce and invited him over for a snack. When Set tried to tell the other gods about last night's events, Horus told him to prove it by "calling" their respective ejaculate. Set's answered from wherever Horus wiped his hand off, and Horus's answered from Set's stomach.
Another interpretation of the myth is simply that Set and Horus were simply trying to outsmart each other, as this myth predates the demonization of Set, and that Horus let Set have sex with him for other purposes. The series of myths this story comes from includes several different contests that Set and Horus had with each other, the point of them being to see who was superior in order to decide who had claim to rule over both Lower and Upper Egypt. Set lost most of the contests due to his Chaotic Stupid nature, whereas Horus won most of them by outsmarting Set and making him look like an idiot.
Germans Love David Hasselhoff: As mentioned above, Westerners loves Isis. Probably because she is one of the few major fertility goddess that is significantly likable than Hera/Juno and Aphrodite/Venus.