As ScottGu announced in the Mix08 keynote today, we now have a full, rich set of controls built in to Silverlight 2.
Kathy Kam recently created a very cool control viewer to show off all the great built in controls.
Oh, and don't forget about the really rich set of controls produced by our eco-system. Just a couple of examples:
Nov '08: Updated the link to the RTM version of the samples page: http://silverlight.net/samples/sl2/silverlightcontrols/run/default.htmlAlso, be sure to check out the Silverlight Control Toolkit: http://www.codeplex.com/Silverlight/