Wizard's First Rule is an interesting and charming story. The world is fresh, interesting, and original. The characters are warm and likable, though some of them are cliched (similar to the way Eddings' characters feel like family, but rarely break the mold.) The story centers on a pair of star-crossed lovers, and their struggle to save their world from a tyrannical madman. Not exactly the most original plot, but with enough new takes on the old theme to be entertaining.
Overall, I found Wizard's First Rule to be an excellent addition to my library. Is it as eloquent as Memory, Sorrow, and Thorn? No. Is it as gritty as A Song of Ice and Fire? No. But it does have its own qualities. Warmth. Charm. Romance. And these qualities are strong enough to make the novel a worthy read.
After the first book, unfortunately, things start to go awry. Goodkind seems unwilling or unable to move past his initial novel. He seems like an author who's been dreaming of telling a single story and now that the story's been told, he's at a loss over what to do. Subsequent novels re-tread the original story's romantic subplot, as well as create concepts that feel tacked onto the original world for the sake of having something to write about, rather than being organic parts of the initial conceptualization. Each novel, some new heretofore unknown threat seems to rear its ugly head, Richard and Kahlan get separated, Kahlan doubts Richard's love (in spite of the fact that he's proven his devotion a dozen times in a dozen different ways,) and eventually Richard "instinctively" learns a new kind of magic to save the day. It's the same story, again, and again, and again.
I'd recommend the first novel, Wizard's First Rule, to anyone. I'd recommend they shy away from any of the others.
As for comparisons between various authors, I think that a lot of the comments I've seen in this thread so far seem to praise Martin's virtues while ignoring Goodkind's. Goodkind's romance (in the first novel,) is light-years better than anything Martin has shown himself capable of up to this point, and Wizard's First Rule has a charm in its style and story that Martin's novels do not. Do I dislike Martin? Absolutely not. I love him. But that doesn't mean he is the perfect writer, that his novels have every desirable quality a book can have, or that authors whose novels display different qualities are less talented.
Edit to add: Those posters who've mentioned Goodkind's "morality lessons" have a very valid point. Although this isn't present in his first book, several of his later novels very clearly want to get a message across. Unfortunately, Goodkind doesn't seem to have learned the same lesson Jennifer Roberson has. In the foreward (or afterward, I can't recall) of one of her most recent Tiger and Del novels, she quite unabashedly admits that the series contains a message (which is certainly obvious when you read it). But, she goes on to say, she's always believed that a story with a message must still, first and foremost, be an entertaining story (which her novels are.) She notes that some authors seem to forget this. Sadly, Goodkind is one such.