I'm not going to tell you you're wrong, I am however going to say in a thread when someone asks for an album recommendation from a band they're thinking of getting into you should generally try suggesting an album that is held to be good by the general fan base. I'm not saying to disregard your own opinion, but you should probably mention your favorite of the albums that are generally held to be the band's best, which would be anything from Divine to Odyssey.
In short, although you might find Damnation to be their best, judging by the fan base at large he has a much greater chance of enjoying one of the other albums I mentioned.
Edit: For example, Scarsick is my favorite Pain of Salvation album, but I know it's disliked by a large part of the PoS fan base, so if I were to give a serious recommendation I'd go with either Remedy Lane or The Perfect Element.