Doug's Fair Lady: Patti and Doug are sharing the same cart on the "fastest ferris wheel" at the fair. Once the ride stops, Patti asks Doug if she can help him out of the cart, and takes his hand. As it's all happening, the fireworks go off.
Patti: Wow Doug, isn't this amazing? Doug: Yes. It really is.
While Doug's in the Money was somewhat bad (Doug returns an envelope full of hundreds of dollars out of the kindess in his heart, only to receive a pack of gum, and losing respect from some of the kid characters), the ending was pretty sweet. When Doug is walking away, his sister Judy drives up to him and offers to take him to the Honker Burger, on her. Considering some of the mean things she's done to him, this was a heartwarming moment between them.
In one of the early episodes Judy is supposed to perform at Doug's school with Doug himself forced to introduce her, knowinghow weirdshe is Doug tries everything he can to get her to change her mind until he sees her backstage as he was trying to hide. She's distraught because they can't find Doug and nervous that she won't do well until Doug comes out of hiding and proudly introduces his sister.
Doug Rocks the House: After knocking down Patti's old house with a rock (to impress Roger and his gang), Patti gets mad at him. Doug doesn't understand why, until he finds a picture of her and her friends at her old house. Skeeter tells him that she lived there until her mom died, so Doug goes to the area where her house was knocked down (it was actually in a construction area), and finds a doorknob, thinking she might remember her old house from it. When he brings it over, Patti tells him it was from her next door neighbor's house, but tells him she'll keep it. Doug at first says she's only keeping it to remind her about how stupid he is, but then she hugs him and tells him it'll remind her of how sweet he is.
"Someone Like Me", a song that Doug sang in the Disney World stage show (and it also shows up in the end credits for The Movie). The beautiful lyrics are really heartwarming.
A subplot of "Doug's Midnight Kiss" (a New Year's episode) involves Judy being annoyed by all the New Year's Eve celebration, brushing it off as "bourgeoisie" and "plebeian", and spending most of the episode trying to avoid it. But near the end, she gives up and sits with her parents to watch a movie, and they end up falling asleep on each side of her. Then, as she watches the ball drop to ring in the new year, Judy kisses her sleeping parents on their foreheads, saying "Happy new year, Mom. Happy new year, Dad", in the sweetest, most genuinely loving tone imaginable. And to top it off, she then blows one of the noisemakers that previously irritated her so much.
"Judy's Big Admission" has Doug going to stay for a weekend with Judy at her prospective college, Vole, where she tries to get admitted. The episode is full of heartwarming moments between Judy and Doug:
After Judy's audition performance is cut off after three lines (because the judges were so tired of watching audition after audition), she's heartbroken at the fact that she probably won't be accepted, and Doug hugs and comforts her.
When Doug finds out that he lost a comic book art contest that he entered, Judy raises his spirits with a speech that uses her own experience with being rejected as an example. This bit really stands out:
Doug: Forget it, Judy, I don't have any talent.
Judy: Well, not talent like mine, perhaps... but you do have talent, Doug.
After Judy admits to the judges that she's been passing off Doug's drawings as her own, Doug convinces the judges to give her another chance, pointing out that he couldn't draw the pictures that he did if they only let him draw three lines. And when Judy does get another chance, she impresses the judges and is accepted - and shows Doug her gratitude by blowing him a kiss.
If you were a kid that was chosen as Quailkid in Doug Live! at Disney World, this was what probably happened to you (as well as a Moment of Awesome) when you were on stage with your childhood hero.
This troper would have FREAKED if she had gotten to be Quailkid in the show! Especially the fact that Roger (dressed as DR. RUBBERSUIT *sighs*...I repeat *SWOONS*!) was right next to him! She'd totally lose her marbles and squeal like a fangirl!
This also must've happened when you got your picture taken with Doug and Patti outside the theater.
During one of the Nick episodes, Doug's aunt, who doesn't really realize he's not 5 anymore and works at a TV station, puts Doug on a really humiliating cowboy show that Roger happens to catch. Roger of course take the opportunity to torment Doug.. until Doug's aunt reveals Roger was also on the show last year to his humiliation. So the two boys decide to have a viewing party of the tapes they received... watching them burn and generally enjoying each others company. Given that Roger spends most of his Nick screen time stalking and tormenting Doug, it's an oddly sweet moment.