I hadn't watched this when it first came out. It was the golden age of syndicated television, and would set the stage for the coming fantasy genre revolution. In fact, many of the people who worked on Hercules would go on to work on Lord of the Rings, Narnia, then back to television with Legend of the Seeker.
Hercules, even in its day, was a throwback to fun, weekly adventures. A bit campy, and not always concerned with continuous or serious storylines, yet it was an enjoyable escape. In our era, where every show doesn't know how to be anything but dark, dreary and overly mature, it is no wonder people are still watching Hercules nearly thirty years after it premiered.
Keep an eye out for early appearances of now familiar stars, or the habit of recasting the same actors in different roles. You'll see the introduction of Xena in three episodes in the first season, though not in great detail (her character wasn't originally meant to survive). She would get her own show in the same universe, though all her circus flipping through the air and other stuff made things too silly at times.
Sure, the special effects sometimes show their age, but they managed to accomplish a lot on a tv budget (and these are the people who would eventually do the f/x for Lord of the Rings). The set designers and costumers built a convincing world (though many interesting costume choices). Features a culturally diverse cast that was certainly not historic for ancient Greece, yet felt organic and not forced (and they did it long before anyone else).
It's funny how many adults say they watched this when they were kids. Not really for young kids, yet it didn't go overboard with adult references. It certainly wasn't afraid to highlight its beautiful women either. So if you want fun tv again, check out Hercules (and see if you can find the hard-to-find tv movies).