While I will say that I believe Geoff Johns' Secret Origin is probably the best one written post crisis, I think Birthright is my favourite, purely for that beautifully poignant moment where Jor-El and Lara actually get to see their son grown up, and they know that he made it.
I almost shed man tears.
"With the first link, the chain is forged. The first speech censured... the first thought forbidden... the first freedom denied – chains us all irrevocably."
I do really like Secret Origin. Even though they're silly by today's standards, the Christoper Reeve movies were my first introduction to Superman and the book really captured that same sort of vibe and the likeness Gary Frank made Clark have toward Reeve was a neat touch.