Buttons
These buttons look great in chrome and other native css3 browsers, they work in IE but dont have rounded corners.

papermashup.com
http://papermashup.com/pretty-css3-buttons/

zurb.com
http://www.zurb.com/blog_uploads/0000/0617/buttons-03.html

Some contenders to use, If you dont care about Internet Explorer at all – these buttons dont work at all in IE – however they look outstanding in CSS3 browsers:
http://www.wearepico.com/buttons/

Menu
Crossbrowser CSS dropdown menu
http://www.webdesignerwall.com/demo/css3-dropdown-menu/

– building on this post when i find worthy elements i use.