Chose your edition to suit your interests
How does one review such a classic? Its literary merits, the appropriateness of the allegory and just how far it stands up to detailed scrutiny, have been discussed in full, leaving little to add. So, here, for what they are worth, are my comments.
I was inspired to re-read this book, which like many people, I first discovered as young teenager (for pleasure, rather than an English literature text), when I came across it recently on special offer. I found that I enjoyed it just as much as previously, but was much more aware of the allegorical aspects of the tale.
As well as the novel itself, my Penguin edition included as appendices, Orwell's own introduction and his introduction to the original Ukrainian translation, both of which I found fascinating reading. Until revisiting this work, I had been unaware of how long it was in the making and how close it came to never being published. It is perhaps worth looking at a number of editions to see which one offers the introductory material which has the most interest for you.
If you, too, wonder how you would react to Animal Farm now, I thoroughly recommend it. Although Orwell's introductions make it clear what the original warning was, I can think of plenty of other parallels which are applicable now.