I achieved my 300th published article at Helium.com recently. Of all the writing sites affected by Google's Panda they seem to be the most innovative as regards fighting back. Expect interesting new developments from Helium in the New Year.
Helium increased their open assignment prices for the Christmas period from $2.00 to $2.50 per article, which was a nice touch. But it's revenue share which writers need to concentrate on at Helium.com. You're unlikely to make more than a few dollars a year on any one article, but, if you're in for the long haul, you'll earn more there than the one-off article payments on other sites.