Hate to be that guy, but my favourite stuff is actually their two earliest albums, but death metal is my favourite metal. Iāve also got a massive soft spot for 80s punk and metal from central and southern America, genuinely some of my favourite music. They donāt use death growls or Cookie Monster stuff, but itās as close as they got, so might not be the best starting point for you.
Beneath the Remains is generally seen as one of the best thrash metal albums ever made, so this would probably be as good a place as any. Chaos AD is also great and possibly a shade more accessible for a non metal fan, so this might work too.
Then thereās Roots. Kind of split their existing fan base at the time - brought in a lot of different elements, including groove metal and some indigenous Brazilian music. Some people think itās a total masterpiece (itās one of the very first entries in esteemed metal mag Decibelās Hall of Fame series for example). Iām not quite on board with it, but it very obviously hits the spot for lots of people.
Max left the band after Roots and Iām not as familiar with their albums after him, perhaps someone else knows these better??
To;dr start with either Chaos AD or Roots. If you start with Roots and donāt like it, be aware that itās not totally representative. If you cant get on with Chaos AD, theyāre possibly not for you.