Overall, Lois & Clark was a mess.
First of all, the special effects were embarassing. Not just bad, embarassing.
Secondly, the show was cheap, and obviously so. It was extremely obvious that Metropolis was a backlot. The sets looked like sets. The props looked like props. Compare this with the stylish, atmospheric movie-like visuals of The X-Files, a TV show which was made in the same period.
Lois & Clark is really a run-of-the-mill 1980's adventure TV show that was made in the early 90's. Plots from L&C could easily have appeared on The A-Team, Knight Rider, etc. Most storylines were L&C investigating some half-assed crime which would result in Superman stopping some half-assed criminal. Compare this with the genuinely dramatic plots on Smallville.
Plus, it was supposed to be a romantic comedy as well. The comedy consisted of Teri Hatcher acting like a little girl.
The relationship between L&C had a certain amount of spark. Hatcher and Cain had chemistry. But it was never convincing as a relationship. Compare this with the doomed relationship between Clark and Lana in Smallville, which is much more believable and effecting.
And finally, Dean Cain is the worst Superman ever.
On the plus side, he was a great Clark Kent.
I used to think Teri Hatcher was the best Lois, but she's not really. She's just the sexiest.
I liek the show, I have the first two seasons on DVD and will likely buy the other two. It's an extremely easy to watch piece of television. I like to watch an episode before I go to bed. But as far as screen versions of Superman go, it's no way near as good as the 40's animated shorts, the 90's animated series, Smallville, Superman, Superman II or Superman Returns.