Self-awareness of advertising

While watching and episode of 30 Rock a few weeks ago there was a scene where two of the characters had a conversation, while at the same time were obviously advertising a product. And the more I thought of it, this was most definitely not the first time 30 Rock had done this. It had consistently not at all subtly put advertising into their episodes. Most notably was a scene where Liz even looks at the screen and asks “Can we have our money now?” http://www.youtube.com/watch?v=aGlFPIg0H6U
But the more I thought of it 30 Rock wasn’t the only show that had advertising that wasn’t at all subtle. That I can think of there are quite a few other sitcoms that have fairly blatant advertising in them, and they are quite a few times that they are being poked fun at.
A good example of another show that pokes obvious fun at their paid advertising is Arrested Development. In the episode Motherboy there is a scene between two characters talking about funding a TV program they plan on making. This conversation is of course taking place in a Burger King. They talk about how its easy to get funding by placing a product in a show “so long as you don’t draw attention to it, while they are sitting at a table in a Burger King talking about how it is a “wonderful” restaurant and emphasizing the fact that you can get free refills. At the end of the episode they even zoom in on one of the character (who wouldn’t even know what a Burger King was, let alone step foot in one) drinking out of a Burger King cup.
While other shows don’t generally poke as much fun at their advertising it is still pretty obvious that they are being paid to promote a product/place. The Office has quite a few corporate sponsors, such as Chilies. Almost every chance they get to eat out or have a business meeting they go to Chilies, there is even an episode where they sing the Chili’s song.
So I was wondering, do you prefer shows to openly admit, and mock their corporate sponsors or would you prefer product placement to be more subtle and in the background?