scatteredlogic was just talking about the state of the American sitcom, and how it seems like really attractive, thin women are paired off with average guys.
I would take this a step further. For the last few years I've been really noticing that this even extends to commercials. You almost always see a geeky, slightly overweight guy with a fairly attractive, thin woman. In nearly every commercial. Not so attractive that they're scary, just pretty in a generic way.
I can't remember the last time I saw a commercial featuring a married couple who were both on the plus side, or with an attractive man and a not-quite-as-attractive woman. Yeah, I'm sure y'all will pull exceptions out of your hats, but still, they're the exceptions, not the rules. In most commercials with goofy-looking guys, the wife is nearly a knockout.
I do remember that I nearly jumped out of my skin when I saw a KIA commercial with actors/actresses who appeared to represent the populace more realistically. That was a campaign from about two or three years ago. Even better, it had some sort of punchline involving one of the heavier woman actually (gasp!) having relations with a guy. (Even though you'd never know it from watching TV, plus-size people actually do fall in love, have sex, and do all of the things thin people do.)