These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Depending on how you see Donny, he's either a figment of Walter's imagination, since The Dude only talks to him once, a figment of both the Dude and Walter's imagination or to put it simply, a real person.
Let's not forget Walter himself. He's either a gun-nut who's never been to the 'Nam, or his behavior is because his friends died there. Or perhaps, it was because of his divorce.
Crowning Moment of Heartwarming: Not many in this film, but there's a small one just before the final fight with the nihilists, when Donnie is frightened and Walter, for once in his life, takes a break from berating him to say that he's not going to let anybody hurt him.
The Dude hugging it out with Walter after Donny's funeral may also count, as well as Walter's eulogy. The first half, anyway.
Cult Classic: The movie's reception upon release was mixed, with a solid budget return for the film's relatively small budget (only two million!). However, we can thank...
"The Little Lebowski Urban Achievers. And proud we are of all of them."
Harsher in Hindsight: The cheque the Dude writes in the opening scene is dated September 11th, and during the same scene, George H. W. Bush is giving his "this will not stand" speech in regard to the Gulf War.
Hilarious in Hindsight: On the rich Lebowski's wall is a mirror mocked up to look like a TIME Magazine "Person of the Year" cover with the caption "Are you a Little Lebowski Urban Achiever?" In 2006, TIME Magazine's POTY was "You" and the cover was a mirror.
Vindicated by History: The film garnered mixed critical reception and meager box office sales in theaters; on home video, it became a comedy classic.
Wangst: Everyone in this movie complains too much about their problems. But no one could match up to the sheer whining that the nihilists gave when they are trying to confront the Dude, Walter and Donny.