I own Final Doom and I love it. There are actually 2 games in Final Doom. TNT: Evilution was my favorite of the two because it had better atmosphere, the other had a higher difficulty.
This is totally awesome and a treat to those of us who love Final Doom, which has very good music. I really dont know which is the original, but this made me install Final Doom again... Uh. That's it. It's good.