Depending on how you look at it, this is either the second (according to Canon) or third (according to me) series of Canonet cameras. They're all fixed lens, 35mm mid-tier rangefindes. The original was a selenium cell, bottom-advance machine. The QL line put the film advance on top and changed to CdS metering.
Now this. Canon called it the New Canonet, even though they didn't brand it that way on the camera body. So cosmetically it looks very much like the earlier QL versions. The big top-off is that these have a hot-shoe instead of a simple accessory shoe; so you can put the Canonlite D flash on it without having to futz with sync cords. The hot-shoe also allowed the camera to automatically set the aperture to allow for the flash, because the camera knew what distance you were focusing on and could adjust accordingly.
The first of the New Canonets was the 17 version. They also put out a 17-L, the L standing for Luxury (as it does on their lenses). Unlike their lenses, however, the only luxury you got was an in-viewfinder battery check.
The 17 stood for ƒ/1.7, its max aperture, but they put it on a 40mm lens (previous Canonets were 45mm). Canon followed this with their New 28 version, which was the down-market, budget version. The max aperture was ƒ/2.8, no self-timer and no QL feature. My guess is that, outside of the original Canonet 28, this is the least desirable of the batch.
There was also an ƒ/1.9 version, but it was discontinued quickly in favor of the next (and last) series of Canonets, the G-IIIs. That would probably make the New Canonet 19 the rarest, but I don't know if that makes it any more desirable. Since the New Canonet 19 and the G-III are actually the same camera, they probably just stopped the production line long enough to glue the G-III badge on it and started up again.
Modern Photography magazine camera test: July 1970
Camera manual: Orphan Cameras.com