I tend to buy new films on Blu-ray rather than DVD, these days. If a 70mm print isn't available, of course.
Well, yeah. I only buy on Blu-ray these days.
I also tend to use the terms as they were intended. All video disks are DVDs, but certain ones are standard definition, unfortunately referred to as simply DVDs and more recent technology includes Blu-ray DVDs, which, depending upon the compression level, are about as High Definition as any consumer can find.
Those collections with four or six movies on one Blu-ray DVD are about as HD as a standard DVD!
I do not think I have bought a standard definition DVD in over four years, except for an ancient movie I love found in a three dollar bargain bin which I had probably not even yet been replaced from VHS days. (The only VHS I still own are family movies and even those are backed up on DVD)
Recently, several Hitchcock films have come available on standard DVD for near pennies and I just grabbed all I could find. I do know that a NEW re-compression of his old filmstock onto Blu-ray would be amazing, but I seem to be unable to resist them at the price of three or four bucks.
Otherwise, I just buy recent movies I am interested in owning on Blu-ray format. Some of these newer movies have incredible sound! Even cartoon movies can have amazingly detailed and deeply engaging soundtracks.