I also have all of their albums... IMO the best one is "Once Sent From..", but they all rule... "Vs. The World" is a bit more deathmetal according to the vocals, but of course it´s still good old Amon Amarth. The sound is also better, and especially the drums has evolved a good sound.
I did some studioreports of AA in connection with "Versus the World", and they are really some cool guys. And yes, they destroyed Wacken as well...
@Nico16 - I can second your oppinions of "The Crusher", and I think the title of one of you fav.tracks is "Masters Of War" (The opening song on Wacken too) or "Risen From The Sea 2000" which both are killers!!!
NP - Trail Of Tears - "Liquid View"