I haven't seen every single one of his DTV movies (as I've heard people that attempted such feat ended up in a criminal asylum), but here is my personal top 10:
1- Out for Justice
2- Above the Law
3- Marked for Death
4- Hard to Kill
5- Belly of the Beast
6- Urban Justice
7- On Deadly Ground
8- Under Siege
9- Fire Down Below
Don't know about n. 10: maybe The Asian Connection (saw half of it and didn't think it was too bad)?
I really want to see Attrition, maybe that will find its way in the list!
Btw, I don't really like Under Siege somehow, the only reason it's on the list is the cake scene...