What were your favorite parts of Up?
For me:
[spoil]Obviously the opening. What really got me was the bit with Ellie sitting on the lawn after she goes to the doctor. I definitely teared up.
The “dream sequence” with Carl trying to get Russell out of the house. That was just too funny.
The camp fire scene was both comedic and touching. It really makes you rethink Russell and his motives.
The dinner scene between Carl, Russell, and Muntz was extraordinarily well written.[/spoil]
[spoil]I just LOVED the entire first twenty minutes, with all of the character development, plus Carl and his interaction with the construction crew. Ellie was such a wonderful character, and seeing their montage as it jumps decades in single frames was extraordinary. Also, the use of Bizet’s Carmen when Carl wakes up in the morning, then travels down his stairs, was extraordinary as well. And my favorite moment in the entire film was that shot when the music ended on the last few notes, and the frame pulls back rapidly to reveal the location of the house in the construction site. Oh god I loved that!
I love films that aren’t afraid to hold onto a single shot for more than one second. 
Too many films today are constantly moving, and to see still frames in Up repeatedly, especially during these first few scenes, was outstanding direction by Docter. I loved the moments where the shot hung on something mundane, such as a photo, or a table, or something. I’m all giddy just thinking about that. Me and my Film Geek-iness.
Also, Ed Asner’s dialogue with the construction crew was wonderful. I think Asner was perhaps one of Pixar’s very best voice artists ever.[/spoil] 
The Toy Story 3 trailer 
just kidding, although it did add a lot to my viewing pleasure 
[spoil]I probably liked the dream sequence and the scene where Carl tries to get Dug and Kevin away[/spoil]
I loved a lot of scenes.
[spoil]In the begining of the movie where we see Carl and Ellie live their lives happily together.[/spoil]
All of the Dug scenes
[spoil]The fight scene between Muntz and Carl[/spoil]
[spoil]The ending when Russell gets his final badge and when he spends time with his new fatherly figure, Carl.[/spoil]
When Alpha has the Chipmunk voice.
Oh God! Where do I begin!?
[spoil]The scenes with young Carl and Ellie. I laughed when he broke his arm because of her. And even just the rest of the scenes with those two in them. They seem like the perfect couple.[/spoil]
[spoil]Carl’s dream sequence when he hopes to get rid of Russell. I LOL’ed when he said, “That’s not gonna work.” XD[/spoil]
[spoil]The campfire scene. That really made me understand why Russell wanted to earn all those badges.[/spoil]
[spoil]When Carl made it to Paradise Falls and looked through Ellie’s adventure book. Seeing that all the pictures were of them was so touching. And at the bottom of the last page that said, “Thanks for the adventure, now go have a new one.” That added to the effect. To Ellie, her adventure was knowing and being married to Carl. [/spoil]
[spoil]When in the end the house made it to Paradise Falls, just as Carl and Ellie wanted it to be.[/spoil]
[spoil]When Carl gave Russell the “Ellie badge.” I almost cried! I mean, Carl had lost everything that was symbolic between him and Ellie up at Paradise Falls! The only thing he had left was that pin, and he gave it to Russell. 
[/spoil]
[spoil]The ending how Carl almost seems to “adopt” Russell as his own. They seem to have a father/son bonding at the end, and it is so touching![/spoil]
As you can see, I have a lot. Heck, this is all I remember at the moment! There’s bound to be tons more!
Hoo boy, I think a better question is what DIDN’T I like. I like too many of the scenes!
I won’t restate I loved the opening sequence, since it’s pretty much a given.
[spoil]1. Carl’s interactons with the construction crew.
“Tell your boss he can have my house!”
“Really?”
“WHEN I’M DEAD!!” slam
“…so, I’ll take that as a maybe?”
2. The incident with the mailbox. Ho. Lee. Crud. That moment was just…wow. I was dumbstruck for the next few minutes by just how incredibly raw that moment was.
When Carl turns off his hearing aid and you see Russell gesturing emphatically in the background. And the sequence that follows.
The campfire scene. It was touching, heartwarming, and many various other cliche “feel good” words.
“Cross your heart?”
“…cross my heart.”
D’aww…
The dinner with Muntz. That man was flippin’ SCARY. I felt so bad for Carl, trying to do a good cover-up and being thwarted by darn Kevin.
When Muntz sets Carl’s house on fire. Dang, man 
When Carl breaks down into a fit of rage about how he didn’t want any of this. It made his character seems so much more realistic. The scene at Paradise Falls where it’s quite clear there’s no joy in this triumph is also superb…as was the Adventure Book sequence.
When Carl saves Russell. That was some great maneuvering on his part.
EPIC OLD MAN FIGHT!
“Any last words, Fredricksen? Well, spit it out!”
spits dentures
XD
When Muntz tries to kill Russell and Dug right in front of Carl. Again, SHEESH. That man was flippin’ INSANE.
The final scene between Carl and Russell, especially Carl’s speech and the hug. EPIC D’AWW!
[/spoil]
[spoil]“Take a bath, you hippie!”[/spoil]
This movie was fantastic all the way through, so I’ll leave it at that!
A lot of great ones have already been mentioned, and I know I’m repeating some - I could also go on forever, but I’d better limit this to a few things:
Regarding Dug: Well, practically everything about Dug! But, specifically, discovering that Dug caused the rockslide to stop the pursuing dogs, and his big “Awww…” line: “I hid under your porch because I love you.” By the end of Monsters, Inc., Pete Docter had convinced me that I wanted to take Boo home. By the end of Up, he had convinced me that I wanted to take Dug home.
Pixar Action Set Piece of the film!: The chase sequence with the dogs pursuing them through the canyon, with Carl riding Kevin, towing the house, and Russell swinging at the end of his tether, while Kevin leaps from rock to rock - that had me giddy!
Seconding one from Castoro Chiaro: Muntz setting fire to the house! That was a real, gasp-inducing, “Oh, my gosh, this guy means business!” moment.
Too much Carl and Russell to narrow it down, but I agree with a lot of what has been previously mentioned. I will add, I loved Russell flying with the leaf blower, and the whole running thing about him being “the Small Mailman.”
I’m sure I could come up with more, but I’d better stop there.
Edit: One more I forgot to include yesterday:
[spoil]The first scene with Kevin being chased by the dogs - the way they managed to “tease” us with the bird, without letting us really see it just yet.[/spoil]
And I know there’s another one I keep meaning to mention and keep forgetting… 
I loved every bit of the movie. But if you’re asking me for a favorite scene then…
[spoil]First thirty minutes of it. Can’t imagine how much heart was put into it.[/spoil]
Too many to count!
I didn`t know whether to be sorry, or to laugh at Carl and Muntz fighting and both throwing their backs out!
I finally remembered the other one I wanted to mention!
When Russell appeals to “Ellie” to let him keep the bird, and tells Carl that Ellie says he can, and Carl actually looks up at the house and says to Ellie, “But I already told him no!” I thought that was a sweet and funny moment.
One other thing that made me go awww…
In the pictures that run during the credits, the picture of Carl and Russell taking the dogs to the retirement home - Alpha sitting with the sweet old lady - I just thought that was a sweet coda for him - although he was still wearing the Cone of Shame!
Without a doubt
[spoil]when Carl reaches his goal of getting the house to Paradise Falls. Most stories would have stopped at this point with a happy ending, but Carl just sits there anticlimactically. He achieves his adventurous dream, but it’s not what he, or the audience, expected it to be. He opens up the adventure book, closing with the message from Ellie which moves him to let go of the past and live his life. She loved him and wanted him to continue being happy more than anything.
It kills me every time.[/spoil]
I’m just going to add spoiler alert to all of this…just to be safe 
Spoiler (Highlight to read)
[spoil]
My thoughts about what’s in the spoiler tag are PG-rated–just putting that out there–keep in mind I’m a little older than many here so some of the themes in the movie resonate with me at a raw, adult level.
This is more of a general statement regarding a theme in the film, but I really appreciate how the movie explores the adult relationship between Carl and Ellie, and how it is so tastefully done in a way where audiences can come away with how natural and healthy it is. And by audiences, I mean children too. Depending upon the age of the viewer, scenes such as the marriage and the possible miscarriage (I’m still debating whether or not it was indeed the loss of a child or the diagnosis by the physician that Ellie was infertile–but the posters on the exam room wall and the immediate scene before of decorating a baby’s room implied that they were expecting), will undoubtedly have a different impact. I have seen some of my friends experience such loss in their lives and observed how devastating it can be, and at the same time seen them bounce back and find happiness again. These raw subjects–human love, sexuality, loss, and recovery are presented in a way that they should be viewed–integral parts of life, rather than over-dramatized and gratuitous.