Black Future. No question.
But as for others that are good: Destruction - The Antichrist, Sodom - self-titled & M-16, Violator - Chemical Assault.
Solid: Exodus - Atrocity Exhibition pt. A, Testament - Formation of Damnation, Lazarus A.D. - The Onslaught (more of a groovy, metalcore-infused thrash)
I honestly don't have much thrash from the last decade.