I'm with you. Diebuster is prolly one of my favorite anime.
I thought it was meh for the first 3 eps. Then I watched Gunbuster, then I watched the last 3 eps of Diebuster and thought it was 'OMG AMAZING' The ending pulled my heart.
I have to agree. I can't really stand Code Geass in general and I haven't watch that much 00. Besides the 8th episode, Macross Frontier has been absolutely stellar.