As to Namek and the Nameks, as much as I prefer King Piccolo and Piccolo Junior being evil magical demons, as science fiction concepts, they're pretty unique; essentially a race of plant-based life forms that fit a natural synergy with their planet, growing "crops" not to feed themselves, but to reforest after a natural disaster. The Dragonballs exist not as devices for fulfillment of petty desires, but as a spiritual quest, with each being held by a village elder entrusted to give it only to the truly worthy. The wildlife is analogous to Earth, with giant crabs, dinosaurs and lizards, which give Bulma something to dodge when she gets stuck on her own. Although many find the Bulma subplot annoying, I feel that it marks a nice break from the fighting action because I'm one of those few DBZ fans that actually tunes in to see how the characters are doing.
Season two of Dragonball Z is not the strongest of the bunch, it does feel padded in places, but overall I feel that it stands on it's own merits. Frieza is still a menacing unknown and the alien setting is brand new, super saiyans are only a legend and Tien, Yamcha, Piccolo and Chiaotzu training with King Kai remind us that, yes, they can keep up with Goku, to a certain extent. I get the sense that the series feels longer because it leads straight into the Frieza saga, so many mistake it all as one chunk from Vegeta fleeing Earth through to the Garlic Junior episodes, which is a mistake, but hey, I get it. If you have bitter memories because you haven't seen this stuff since school, maybe check it out one more time, just make sure you get the uncut DVD versions, not the broadcast stuff.