XNA Stuff
Tutorials
Microsoft's Easiest XNA demo
http://www.xnadevelopment.com/
http://rbwhitaker.wikidot.com/xna-tutorials
http://xnagpa.net/xnatutorials.php
http://en.wikibooks.org/wiki/Game_Creation_with_XNA
http://www.riemers.net/eng/Tutorials/XNA/Csharp/series2d.php
(menu on the right side-bar)
http://xnaresources.com/default.asp?page=TUTORIALS
http://mort8088.com/category/tutorials/xna/
YouTube:
http://www.youtube.com/watch?v=Kxs1iHwUhA0
http://www.gamedev.net/topic/532705-animated-gifs-with-xna/
Animated Gif support
Platform Game Examples
Interesting Game Mechanics:
http://www.youtube.com/watch?v=B_xYBsigJ-U
Cool nose ring:
http://www.youtube.com/watch?v=tcD7LMDNG0w
Spelunky:
http://www.youtube.com/watch?v=TCswu85rJYY
Playing Infinite Mario:
http://www.youtube.com/watch?v=5aoBGpdZoNw