You used to be able to get the Daz gen 3 figures for free, Antonia is free, Apollo is free although there seems to be problems with the DL links (hope the creator didn't end the figures availability).

V4? a virtual money pit. Because she is the reigning queen of Poser figures as far as support goes it's probably worth the investment if you want to create the kind of imagery that haunts the Poserverse.

Antonia and Apollo(?) seem to be the great freebie couple.

http://www.sharecg.com/v/51383/gallery/11/Poser/Angela is a VERY nice free figure, though not a lot of support. See http://www.sharecg.com/AllenArt for some nice things for the figure.

...and others.