I find the show is pretty much offensive on all possible levels. Penny is a dumb slut obsessed with clothes and fashion and she's presented as "normal". That's pretty degrading and insulting to women.
But really, it's a sitcom. Sitcoms are (with the exception of Home Improvement) fucking terrible. The dumb and ugly husband/smart and hot wife dynamic is so fucking terrible that it deserves to be a registered crime against humanity or something. Even on BBT, where the guys are the smart ones, they are still presented as the dumb ones because they're just soooooooo weird omg!
I hate BBT, and sure, I hate it a bit more than most sitcoms because it happens to poke fun at shit I enjoy. But if you take that part out of it it's not any more or less trash than Everyone Loves Raymond or King of Queens or any other complete fucking pile of garbage Shitcom. They all make me want to invent time travel and murder the laugh track and also possibly Ray Romano.