I am not the biggest thrash metal fan. Sure, I like most of the classics, but for me, Thrash Metal was merely a stepping stone to Death Metal. But Forced Entry's 1991 album "As Above, So Below" is a groundbreaking and mostly unrecognized classic with thrash.
This has the usual humor and good time feelings that is inherent in most thrash, but it is also wholly unique in the fact that it sounds like no other band. This band was fairly short lived, had only two full length albums, this one being their last. Check this out if you are not familiar, it is undoubtedly worth it.