Personally I'd go with a Shotgun (Moss 500 or Rem 870) . If you don't have one yet, that's the direction I'd go.
Otherwise I'd say the SKS actual battle rifle, not a made for import version (built heavier and better) cause... that's what I've got, and that's what I know.
I'm forced to ask the age old question of "what are you going to use it for?" All of my firearms have intended purposes (well, some of them are just awesome and I absolutely had to have them). But on a serious note, knowing what your needs are would really help entice some helpful responses.