For example, The Sopranos is an hour-long Tropicana Orange Juice commercial. It's shown in every episode.

Flutie Flakes are seen in the Barone kitchen on Everybody Loves Raymond.

Maybe they couldn't get permission to use the real name, but on Coach, Luther Van Dam often has a donut bag which looks exactly like a Dunkin' Donuts bag (pink lettering on white), only it reads Donuts Donuts instead of Dunkin' Donuts on the bag.

Any other real products or fictional products posing as real products shown on TV shows?

Mary Hartman, Mary Hartman is filled with them. They weren't paid to use them, but they didn't cover up the lables and referred to them by name.

I've always been curious about product endorsement in films and television....how the process works.

The advertisers will pay a movie a certain sum of money for their product to be included in a scene. It has become big business.

The Beverly Hillbillies always had Kelloggs Corn Flakes on hand. Kellogg was their sponsor so the Clampett's made several commercials for them.

Jethro eats giant bowls full of Kellogs Corn Flakes. Jerry Sienfeld's love for cereal is an issue on the show quite often. And sometimes you can see the boxes in his cupboard well enough to tell what kinds of cereals they're supposed to be. Once in awhile he is eating cereal on the show. I remember Kramer, in the episode with the Cable, Guy was carrying a bag of groceries. Sticking out of the bag you could clearly see a bag of Rold Gold Pretzels. George did advertisements for them. But not until after the show was off the 1st run air--I think.

Product placement on TV shows and movies became big with the movie ET with Reeses Pieces, I remember the producers wanted to use M & M's but they were denied permission. After the release of ET sales of Reeses Pieces shot up through the roof.