And when you're done crying, explain in what context you mean "song" and "music" and we'll let you sit at the grownup table for a little while.
Also, V, I agree 'Groove Metal' isn't a genre. It's just the commonly used negative conntotation applied to bands that ornery thrashers find too slow. Pantera, Machine Head, and certain albums by Sepultura, Overkill, Death Angel, Exodus, etc. (you know which ones...most of them happen to be awesome).
I just find that style to be superior to a lot of the korny kVlt krap coming out of the supposedly artistic black metal genre. You know, music espousing "culture" and "values" instead of, you know, music.
Post-thrash? Meh. If we follow the trend of what "post-" genres are, I'd say post-thrash is stuff like Coroner, Mekong Delta, Voivod, and some Annihilator.