I definitely agree with you about prefering Thousand Swords over The Celtic Winter. Thousands Swords is one of the genre-defining black metal albums, an absolutely essential purchase for any black metaller. The whole black metal list is pretty great; I might switch out Sacramentum for the first Dissection album or one of the better Hellenic black metal albums (Non Serviam and Kingdom of Endless Darkness come to mind), if only to cover all of the style's bases.
Personally, I think that Like an Everflowing Stream is one of the most essential albums on the death metal list. It is by far the best and most coherent example of everything great about the Stockholm death metal style with a minimum of that scene's little degeneracies (i.e. no real death'n'roll stuff or overly sappy melodies). Mental Funeral definitely should be on there somewhere, however; maybe it could be switched with Morpheus Descends or Massacra. I'm really just nit-picking though; that list got me started on death metal back when I was a young teenager.