There might be very good episodes of Trek, but nothing is a masterpiece. Trek fans will discuss Star Trek, no matter the vintage or quality. The true mark of genius is whether or not it’s still part of the public consciousness. I don’t know that I’d call TOS a masterpiece, but it’s being very much in the public consciousness says volumes. TNG was extremely important in its time, but I have to ask if it has the same cultural appeal to the masses than it does to regular Trek fans. The rest of the series, even the current crop, barely made a blip. The Kelvin films certainly had an impact.