Death is hard to find w/o the growling, although I find most Opeth not only tolerable as far as the growling goes, but the music itself is fantastic.
When I need my metal dose, I usually stick with the classics, like Metallica, Megadeath and of course Pantera. You might try some Deftones as well for a more Hardcore approach. Id also HIGHLY recommend the new Korn album (yes, Korn) its a terrific piece of work with elements of Hardcore, Metal and Industrial throughout.
If you want to try some artsy-more progressive Metal, checkout the Sense Apparatus by Frantic Bleep ala an ASMOX recommendation. Again, another album that contains a variety of metal elements, great singer, tremendous music-a real gem.
Lastly, I find most people who like speed/death metal really like Ministry. More aggro-industrial here but IMO contains a nice array of "metal characteristics". If you dont own Land Of Rape and Honey, Psalm 69 and A Mind Is A Terrible Thing To Taste, wel...then...you need to get ur head examined.