(n.b This review refers to the Richard Pevear and Larissa Volokhonsky translation). I'll keep this review quite short, as there are plenty of others detailing just why this is regarded as one of the all-time great novels.
As this was my first experience of reading Tolstoy, I had been slightly daunted by the literary (and literal!) weight of this novel. Happily, I found that "Anna Karenina" was instantly accessible, in terms of both narrative and style.
The story is a classic tale of a tragic love affair between the beautiful, highly-strung Anna - one of the most complex and authentic portrayals of female psychology in literature - and the passionate, ambitious Count Vronsky; two people whose intense, complicated loves are not enough to prevail over personal misunderstandings and setbacks from Russian high society. Their story is set into relief by the story of Levin, a landowner struggling with his meditations on life, love, work, religion...All of this Tolstoy deals with insightfully and with an engaging wit. The parallel stories were equally absorbing, and the tragedy of the eponymous heroine particularly moving. I believed absolutely in each of the main characters (perhaps with the exception of Kitty, the object of Levin's affection), whose virtues, vices and internal reflections are described with remarkable depth and empathy. My only criticism is that the last section is something of an anticlimax to an otherwise captivating read.
I can't comment on the comparative merits of this version, as it is the only one I have read, but I found it very fluid and bright, and I will certainly choose Pevear and Volokhonsky's translation of "War and Peace" when I get round to reading it.