Similar to cultural differences in representation of black metal (i.e. Sacramentum vs. Beherit), Finland and Sweden offer varying perspectives on death metal as well.
SWEDISH DEATH METAL
This genre is characterized by a propensity towards highly melodic passages. Most Swedish death metal bands share in common with Entombed a love of Iron Maiden, and subsequently a desire to leave little room for ambiguous musical space, except by way of reverb.
Excepting what's already been mentioned by other posters (i.e. Dismember, At The Gates), exemplars include:
Afflicted - Prodigal Sun
Eucharist - A Velvet Creation
God Macabre - The Winterlong
Hypocrisy - Penetralia, Osculum Obscenum
Seance - Fornever Laid To Rest, Saltrubbed Eyes
Unanimated - In The Forest Of The Dreaming Dead
Unleashed - Where No Life Dwells, Shadows In The Deep
FINNISH DEATH METAL
A reflection of the local black metal scene, Finnish death metal incorporates geometric structures and a dark sense of humor into their compositions. In addition to Demilich and Adramalech, you should invest in the following:
Demigod - Slumber Of Sullen Eyes
Sentenced - Shadows Of The Past, North From Here (especially the latter; a highly underrated album)
Unfortunately, early Finnish metal is not as well marketed as the rest of the Scandinavian catalogue. I'll have to look further into this myself!