i don't really think i have a favorite paper negative stock ...
i just use what i have on hand .. sometimes it is rc, and sometimes fiber
sometimes graded, sometimes vc.
i don't usually flash the paper ...

( from left to right )

ilford fb ( 8x10 )
expired kodak poly fiber ( 8x10 )
expired kodak rc paper ( hand rolled spool 122 size )
kodak polymax fb ( 8x10 )
afga expired, grade 1 ( or 0 ? ) ( 7x11 )

they were all rated around asa 3, but the portrait was 3x slower than that.

all processed in ansco 130 ( except the rc was developed in coffee )