That’s why Cast Away really surprised the hell outta me.
Filboid Studge is the ultimate fictional brand name. 
Crelm Toothpaste, from Monty Python.
Sometimes they only remove part of a letter. I remember seeing on either Friends or Seinfeld a vending machine in the background that was stocked with “N & N’s” candy.
That made me laugh pretty hard.
-Joe
Seinfeld often used real brand names, particularly for candy like Jujyfruits and Junior Mints. However, they also had the occasional made-up brand names like Hennigan’s Scotch and Atomic Subs. For a while, I thought the bookstore called Brentano’s was another made-up business, but it turns out that they have the chain of bookstores in some places up north (no place around here, though).
In DC comic books, the superhero Martian Manhunter from the Justice League was addicted to Oreo cookies back in the 1980s Justice League International series. However, in more recent comics (even ones that refer back to the originals), the chocolatey sandwich cookies he loves are referred to as the made-up “Chocos” brand.
Some of it was made up, but not all of it. I’ve had beer in blue and white cans that just said BEER on them. My cheap friend used to buy it all the time.
At least one made up brand-name from Seinfeld was done out of necessity. In one episode, Kramer feeds pasta to a horse that runs a horse-drawn carriage, leading to a gassy result. I remember reading in one of those magazines that was published when Seinfeld ended that Chef Boyardee didn’t like their product being used in such a manner. So instead of Beefaroni, the pasta Kramer was using was the similar-sounding but fictional Beef-A-Reeno.
Likewise, folks in DC comics drink Soder Cola and eat at Big Belly Burger.
There are regional differences, in the greater Gotham City area Zesti Cola and O’Shaugnassey’s are more popular.
The Tarantino-verse also has Big Kahuna, that Hawaiian burger joint. I hear they have a tasty burger. For retro-kitschy dining, there’s also Jack-Rabbit Slim’s.
I hit enter too soon. I should have mentioned that they also have McDonald’s and Burger King.
True, Cast Away’s use of Federal Express was an exception. However, since Fed Ex transports objects like documents and volleyballs rather than people (aside from the pilots and Fed Ex employees), the fact that its plane crashes in the movie would not be as counterproductive to the company’s image than a real airline like United or Southwest foolishly allowing itself to be used in a fictional movie about a plane crash or hijacking.
If we’re going with comic books, Astro City is replete with “Beefy Bob’s” burger joints, complete with the hat-and-scarf-wearin’ cow. Hey, it was good enough for Samaritan and Winged Victory’s first date…
The show Kingdom Hospital used the fake soda brand “Nozz-a-la Cola” in every episode. They’d go to great lengths to include a Nozz-a-la bottle or logo as often as possible. There was actually a real reason for this: It was in inside joke for fans of Stephen King’s The Dark Tower series. In one of the Dark Tower books, the main characters end up in another universe. They figure out that it’s another universe by noticing a bunch of unfamiliar brand names, including Nozz-a-la Cola.