The short version:
I recently saw The Prestige, and I thought at first that I was going to dislike it. It's actually quite a good drama, with just a teensy aspect of fantasy. Actually, I'd say that it's great, but certain parts rely a bit on the audience not knowing all of the details of the story, so once you've seen it once, I'm guessing that it's much less entertaining the second time around, in the same way that The Sixth Sense is quite an entertaining movie, but not as fun on your third viewing. But, besides those little plot secrets, Prestige is well-written and well-acted, and I enjoyed it a lot. I don't even want to mention anything about the plot of the movie, because that's what made me not want to see it in the first place. If you really want to know more about it, you know how the internet works...
If you haven't seen it yet, I highly recommend it. A first-time viewing is a solid 9+/10, but probably drops to about 6/10 the second time around, so I give it an average of 8.