（16×16）做些工具栏和菜单栏以及状态栏图标最合适不过了
iconset:fugue-icons-16px
http://www.easyicon.net/language.en/iconsearch/iconset:Fugue-Icons-16px/
https://www.easyicon.net/language.en/iconsearch/iconset:16px-application-icons/
iconset:silk2
http://www.easyicon.net/language.en/iconsearch/iconset:silk2/
splashyIcons/
http://easyicon.net/iconsearch/iconset:splashyIcons/
iconset:fugue
http://www.easyicon.net/language.en/iconsearch/iconset:fugue/
iconset:max-mini-icons
http://www.easyicon.net/language.en/iconsearch/iconset:max-mini-icons/
(32*32)
iconset:essential-toolbar-icons
http://www.easyicon.net/language.en/iconsearch/iconset:essential-toolbar-icons/
:fatcowhosting-icons
http://easyicon.net/iconsearch/iconset:fatcowhosting-icons
48*48
flavour/
http://easyicon.net/iconsearch/iconset:flavour/