Sometimes with TV shows. I got a DVD instead of a blu-ray of a movie by accident once, and I had watched it twice before I realized it was a DVD. Anamorphic DVDs can look very very good.
I buy DVDs all the time. The quality of DVDs is much better than it used to be. With modern TV shows and anamorphic stuff, it isn't easy to tell the difference with normal viewing. There is a whole world on DVD that doesn't exist on blu-ray.