Eli Bendersky's website I felt that this book is _really_ about people. Their personalities are worked out so well, you can really feel what they feel sometimes. At the beginning, I had a weird impression that all the characters are presented as good people, but somehow the interactions between them make some look worse and some look better. Here's a walkthrough of the main characters and what I think about them:
Levin - he is the best character of the book, IMHO. The one I most "agreed" with. He is positive all way long. A simple good hearted guy on one hand, a progressive philosopher on the other. I was amazed at his thoughts about "life". Thoughts about the existence of god, about a meaning of life, about "why we're here". It's amazing that 130 years ago (the novel was finished in 1877) people have thoughts similar to the ones we're having now, and that's despite the fact that life today is very much different from then.
Kitty - She's the most passive main character, I think. Except for some "action" during the Vronsky-Levin choice and the time when Levin's brother was dying, Kitty is, IMHO, just a supporting character for Levin. She guides his thoughts, through which Tolstoy reveals some views on women and families. Kitty is an "all good" girl, aiming at a dedicated house-wife, just like her sister.
Vronsky - at first he is presented as a negative figure, but all in all I hardly find anything wrong with him during the whole novel. The eventual failure of his relations with Anna, is in my opinion solely her fault. Vronsky moved through life using all the aims he could, and it's not his fault he was born "with a silver spoon in his mouth".
Karenin (Alexander Alexandrovich) - a very gray person, but good nevertheless. His relations with Anna was very weird and not real-husband-and-wife like, but that's because of his nature and because she never loved him in the first place. Can you blame a person for his nature ? I can't. Karenin is pragmatic, pedantic, a perfectionist. He's very successful in his work, because he's smart, but sadly highly unsuccessful in his personal relations. I admired his clear, mechanic view of things sometimes. I think that for many situations, this is the correct approach to life. You must know when to look at a situation with a clear, rational view, weighting all pros and cons carefully. Even his sentimental nature came out when Anna was sick after the birth of the girl.
Anna Karenina - At first she is presented as a great woman, admirable by everyone. To be honest, this goes on until the end, eventually even Levin falls in her charms, even if for a short period. My opinion of her is highly chauvinistic, but that's what I feel... She, IMHO, represents many of the falsities of women. Some things in which women are especially annoying and irrational are magnified in Anna Karenina. She always tries to catch everyone's attention. Aware of her appeal, she knowingly makes men interested in her, mostly just to "play around". In the end, when she's on a vendetta on Vronsky, these effects are really shown, when Anna's thoughts are revealed, but really it goes through the whole story. Her obsession on Vronsky is sick. She makes his life a living hell, just like Karenin's. She becomes envious, irrational and heads herself to desctruction (taking Vronsky with her). The end was appropriate for her, I think. It saved Vronsky from more suffering (and maybe even her son's, with whom she also developed an obsession, though of a different kind).
There are other characters, like Stiva and Darya Oblonsky, Levin's brothers, Kitty's parents and many friends of the families. All of these are not so important, I think, though some (not very good) things can be said about Stiva (who is Anna's brother... it's in their blood I guess). What's for sure is that these characters played their roles brilliantly, supporting the main characters and helping develop a great plot.
The book is very readable, Tolstoy doesn't delve to long descriptions, and most important doesn't spend lots of time describing details irrelevant to the main story-line.
Very highly recommended !