WordNet (r) 3.0 (2006):

unashamed
    adj 1: used of persons or their behavior; feeling no shame [ant:
           ashamed(p)]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "unashamed":
   bold, brazen, brazenfaced, exhibitionistic, flagrant, forward,
   griefless, immodest, notorious, regretless, remorseless, shameless,
   sorrowless, unabashed, unblushing, unembarrassed, ungrieving,
   unmodest, unregretful, unregretting, unremorseful, unrepining,
   unrueful, unsorrowful, unsorrowing, unsorry