I wouldn't consider SFAM a modern era album (being 12 years old), but since it's on the list, I am compelled to vote for it. Second would be SDOIT, which, I probably wouldn't consider it to be a modern era album either. After that, I'd say 8VM.
I think the best way to break up DT Eras would be like so: Early (Demos, WDaDU, I&W, Awake, ACoS), Middle (Fii, SFAM, SDoIT, ToT (The era whence the change in evolution in their sound is most obvious to me)), and Modern (8VM, SC, BCSL, & ADToE)