I heard Cannibal Corpse's Tomb of the Mutilated for the first time and then learned about Death and Venom

...And the rest is history!

For me it was Death when I listened to Symbolic for the first time. That heavy opening riff hooked me immediately

Actually i'm not a death metal fan, but at some point i really enjoy this genre!
one of the albums that made me hear it was 'Horror Vision' by Deadsquad

It was Leprosy, Spiritual Healing, Slowly We Rot, Cause of Death, From Beyond and Severed Survival, really old school death metal that wasn't oversaturated with blastbeats and other later genre cliches. I was a huge fan of thrash metal back then, so the old school stuff wasn't that hard to get into.

I heard Seven Churches when it came out, and thought "eh, this is pretty cool, but I like this better" (this was SOD, Big 4 album releases, Iron Maiden, Mercyful Fate)

then heard Scream Bloody Gore and thought "hey, this is real cool, but I like this better" (this was King Diamond, Voviod, Savatage, Hellowen)

then I heard Malleus Maleficarum and thought "hey, this is fucking incredible, I like this as much as anything released this year"
then I heard Altars of Madness and that was all she wrote, and even the boredom of Slowly We Rot couldn't turn me away

Technically speaking, when I started listening to metal, it was with Born Of Osiris and Aversions Crown, which, although they're deathcore, are not too far from death metal. Then, I got into Dissection, which I consider more black metal but a lot of people think are death so that's our second candidate. Really though, I finally got into the genre through Cynic, Death and Atheist. At this point in time I was quite a proghead so it's the prog part of their sound that brought me in more so than anything else, but damn that was worth it

For me it was Cannibal Corpse, because I was 13 and liked how much blood was on the album covers. The novelty of the extremity was enough to carry me through not having any particular context or appreciation for the whole style, since at that point I think the standard-issue thrash survival kit was about the heaviest stuff I listened to. Eventually, though, I listened to Tomb Of The Mutilated enough times for the street cred that I started to enjoy it for real.

Dew-Scented, Eluveitie, The Faceless, and probably Amon Amarth were instrumental in helping me acclimatize to harsh vocals, and while none of those is death metal in the traditional sense, I had to go through a lot of side doors in order to get used to the sound of death metal. I also worked my way backwards through Death's discography, since The Sound Of Perseverance is such a unique album that I think it's an easier sell than Scream Bloody Gore for someone who doesn't quite know how to listen to extreme metal yet. That was all in my early teens, and I think it wasn't until I was closer to 20 that I started getting into Morbid Angel, At The Gates, and Entombed and got reasonably comfortable enjoying death metal on its own merits without some kind of special injection of melody or aesthetic reason to make it novel.