Doug and his dad
I think it's interesting how Doug's relationship with his father is depicted in the show.
On several occasions, Doug goes to his dad for advice, and on several other occasions, his dad gives him some unsolicited advice.
Whenever Doug goes to his dad for advice, his dad seems confused by what Doug's asking him and isn't really sure what to tell him as a result.
Whenever Doug's dad voluntarily gives him advice, Doug doesn't really understand it, or thinks it's not really applicable to his situation, and brushes it off until later in the episode when he realizes his dad was right.
You get the sense Doug's dad may be more or less what Doug is like when he grows up, but at the moment in time in the show, they're just not on the same wavelength. This forces Doug to arrive at the solutions to his problems more on his own.
It's also funny watching Phil's reaction to Judy in some scenes. One of my favorites is in "Doug's No Dummy" when she's crying over the "political artistry" of Doug's ventriloquism, and he sits there dryly saying, "Judy, are you all right? Judy? Judy?" with a blank, fatigued, resigned expression on his face. You can just read the character's mind. "What in the world kind of daughter do I have here?" He's just baffled and completely worn from all the years of her weirdness. He's laid back, but he also seems to be burned out from his family. He's a pretty sympathetic character.