2D Physics Simulation Grand Piano Silverlight Mind Map
3D Teapot Demo Infragistics Controls Demo Silverlight Pad
Amazon Search Visualization JavaScript / .NET Chess Silverlight Playground
AOL Social Mail Gadget Laugh-o-Sphere Silverlight Rocks
Binary Clock LiveStation SilverNibbles
Browser Poker Matrix Digital Rain Smalltalk on Silverlight
Bubble Factory Michael’s Journal Sprawl
Bubblemark Office Ribbon Surface Prototype
Comic Book Viewer Photopoints Gallery SVG to Silverlight Converter
Destroy All Invaders Popfly Telerik RadControls 3D Cube
Digger Python Console Verlet Integration Algorithm
Disco Dance Floor Reflecting Graph Windows Journal-to-Silverlight Converter
Dr Greenthumb Reflector for Silverlight Windows Vista Simulator
Dr Popper Roxio Buzz XamlWebPad
GlyphMap Sierpinski Triangle XPS Viewer
GOA WinForms Demo Silverlight Airlines Demo Zero Gravity
Gradient Animations Silverlight Chess Game Replay

I should probably just add the warning that even if some of these samples are downloadable, (just in case you feel like to play around with them) and come from verifyable sources,  some antiviruses detect the js code as an embedded trojan or an unknown virus. (This happens mostly with AVG, NAV and Kaspersky.)