From 1987-1993 a powerful subset of the death metal scene flourished in Sweden, thanks to a comfortingly depressing climate, public funding and a society able to tolerate such nihilistic music. These bands took the simple chunky blasting of American death metal bands and put its structural evolution to a new type of sound that relied on the fast strumming of chords and heavy digital distortion to overlap harmonic layers into smooth, columnar sounds.
Undeniably, Nihilist and Unleashed were the founders, but the former soon broke up and spawned Entombed as well as Carnage, later Dismember, and influenced other bands such as Therion, Unanimated, At the Gates, and Necrophobic.
If you like the Swedish death metal sound, you might pay attention to these bands from other countries: Demigod, Amorphis, Intestine Baalism, Divine Eve, Fleshcrawl. For more reviews like these, check out the Dark Legions Death Metal and Black Metal Review Archive.