I'd pick up dvd-sets of just about any vintage-WB series, but I have to admit I somewhat share the views of Gary and Neil. The series are 'genre' shows to a dogged degree, unlike many of the more character-study efforts that began to typify hour-long dramas at the time (which are my preference). Nonetheless, the WB shows can offer some breezy entertainment when one is in the right mood for such a thing.
Of the cookie-cutter shows (meaning, excluding later series like "The Dakotas" or "The Gallant Men"), the one I'd most go for is probably "Hawaiian Eye." It's funny, because when I first caught the series during the Goodlife-tv reruns a few years back, I'd determined it was the worst of the lot. The first episodes I watched served up the most moldly old plots (undoubtedly left over from 1930s-era b-flicks), the most cheesey studio-bound backdrops, and the most cliched dialogue. But as I continued to watch the series, the darned thing actually grew on me. There was ultimately something endearing about it, even in its weaknesses. Like, once I accepted the 'fakey' studio Hawaiian backdrop, it became not so much grating as somewhat surreally inviting, akin to classic-era Hollywood product. And, the leads were exceptionably likeable. Conrad and Stevens always managed to liven up a scene, and even the stiff and stolid Eisley, who always seemed like a down-to-earth guy who was totally and self-consciously uncomfortable playing a 'suave' ladykiller-type, was also very agreeable. So, yep, I'd put "Hawaiian Eye" on the top of my list. Sure would be curious to see "Conflict," though. And, the half-hour "Lawman" is a pretty reliably enjoyable, too.