That is, the Lensman series by Edward E. “Doc” Smith; the one my license plate is from.
I wrote this originally elsewhere, but it’s so long, and represents things I’ve been thinking through for decades, I decided to record it here to keep it around.
So. My thoughts on the best reading order:
You can’t win. (Also the first law of thermodynamics; but I digress.)
They were written and published in the magazines, as has been explained, as Galactic Patrol through Children of the Lens. Original publication order is nearly always a reasonable choice for anything famous—that order is how it earned its fame, so it can’t be a horrible choice.
I personally love a few things in Triplanetary all to bits (Rome and WWII), and rather dislike the actual story Triplanetary. And it’s certainly not an introduction to the real series. Plus it gives away in the first introduction all the secrets that were kept through the original 4 books, and gradually released to great effect.
First Lensman is a huge favorite of mine—largely because I love watching him back-fill all sorts of things given us in the basic 4-book series without explanation. That might be okay as a starting point also, or people might wonder why time was being spent on where weird names came from.
(Those two were assembled and published starting in 1950, when the series was first published in books, the Fantasy Press hardcovers.)
The versions of the basic 4 books have been revised to also give away the things that were kept secrets in the magazine versions—so you can’t have the experience of reading them as people really first read them, without tracking down the magazines (hint: the issues with Lensman novels in them are kind of expensive).
(And The Vortex Blaster as published in book form at least is solidly set in the Lensman universe, but is not fully compatible with it and it’s not a Lensman story. I love it all to pieces too, for its own reasons, though.)
So—my recommended approach is to read Galactic Patrol, Gray Lensman, Second Stage Lensmen, Children of the Lens, Triplanetary, and First Lensman. And The Vortex Blaster. But every possible reading order has some points against it.