In Reply To #1
Maybe CotM, but HoD was just so bright in it's pallette it was hard to take seriously. Aria seemed to be in the middile, where DoS was probably on the same level in terms of atmosphere (Aria's still the better game, IMO. DoS sucked.)
Basically, from lightest to darkest:
Harmony of Dissonance
Portrait of Ruin
Dawn of Sorrow
Aria of Sorrow
Order of Ecclesia
Circle of the Moon
The reason I put Ecclesia over Aria in this is purely because of Aria's script. The dialogue was pretty downright cheesy in Aria in several spots, especially when Soma first meets Graham and Yoko, whereas Ecclesia tried it's damnedest to stay as serious as possible.