Definitely ADTOE -> DT12 -> The Astonishing
I like ADTOE, but their last 2 albums are their weakest besides the debut. I agree, there's a great 45-50 minute album somewhere in TA, and the sound is alright. DT12 suffers from many problems both with composition and sound production, and I don't really care for any of the tunes, Enemy Inside is OK, but still feels rushed and unfinished, like the ideas could have been fleshed out a little more. My favorite part of DT12 is the little Easter egg at the end, I could listen to an album's worth of that stuff all day.