Oryx and Crake, and the second, The Year of the Flood.
I was at a bit of a disadvantage with the third because I didn't remember a lot of the details of the first two books - or it took awhile to recall them and put the pieces together. The book was good, but a bit disappointing in tying up the loose ends of the story. It seemed to jump into story lines too quickly and didn't do a very good job of resolving the story of Adam One, the same Adam One that created the Mad Adam game, the title of the book. I don't say these things lightly either, because Atwood is one of my favorite authors. It seems like she was in a hurry to finish the series and be done with it.
Also, not to give any spoilers, but the book ends in such a sad (and at the same time optimistic) way. Although the ending Atwood chose doesn't surprise me, it was hard to digest - especially after investing so much in the characters over three books. While I didn't love the final book, I did love the series.