I can see arguments made for Cannibal Corpse, Death, Bolt Thrower, and Vader. I chose Immolation. 11 Amazing albums of crushing death metal and even the weakest one, Kingdom of Conspiracy, is still a 7/10 for me. I have always appreciated that Immolation while being blasphemous goes about it in a mature and nuanced manner, at least, for a death metal band.
Morbid Angel would be a contender if not for that album they released in 2011. Altars of Madness is one of my all time favorite death metal albums.
Malevolent Creation has a very inconsistent discography. I enjoy Ten Commandments, Retribution, Stillborn, and Individous Dominion, but there was that period in the 90s where they released some duds with Eternal, In Cold Blood, and The Fine Art of Murder. They must have some poor record deals because there are bunch of shitty compilations and live albums from the 90s - 2000s period. Some record company must have been trying to squeeze them for every penny.