'The Candidate' and then 'Across the Sea.'
I loved 'Ab Aeterno.' Found it to be one of the season's (hell, one of the show's) best episodes. Richard's past was fascinating, and I'm loving seeing how those events ripple into the present day story.
Spoiler
The scene with him communicating with his wife through Hurley was especially great. And more Jacob and Man in Black interaction is always a great thing!
Also, couldn't help myself; I had to order
this.