Birthright might be my favorite origin if Waid had stuck the landing. The idea of Lex attacking Metropolis with a holographic Kryptonian army just doesn't work for me, as far as origins go. But the first half is some of the best Superman/Clark Kent stuff I've ever read. I adore that first half of the series!
Morrison's Action origin is my favorite, hands down, but if Waid had pulled off a better ending for Birthright it'd give Morrison a real fun for his money.