Como gerar?: http://www.favicon-generator.org/
Link sobre: http://tableless.com.br/favicons/
<!--Tamanhos para desktop e Android-->
<link rel="shortcut icon" href="/favicon.ico">
<link rel="icon" sizes="192x192" href="/favicon-192x192.png">
<link rel="icon" sizes="32x32" href="/favicon-32x32.png">
<link rel="icon" sizes="96x96" href="/favicon-96x96.png">
<link rel="icon" sizes="16x16" href="/favicon-16x16.png">
<!--Para dispositivos Apple-->
<link rel="apple-touch-icon" sizes="180x180" href="/apple-icon-180x180.png">
<link rel="apple-touch-icon" sizes="152x152" href="/apple-icon-152x152.png">
<link rel="apple-touch-icon" sizes="144x144" href="/apple-icon-144x144.png">
<link rel="apple-touch-icon" sizes="120x120" href="/apple-icon-120x120.png">
<link rel="apple-touch-icon" sizes="114x114" href="/apple-icon-114x114.png">
<link rel="apple-touch-icon" sizes="76x76" href="/apple-icon-76x76.png">
<link rel="apple-touch-icon" sizes="72x72" href="/apple-icon-72x72.png">
<link rel="apple-touch-icon" sizes="60x60" href="/apple-icon-60x60.png">
<link rel="apple-touch-icon" sizes="57x57" href="/apple-icon-57x57.png">
<!--Para favoritos na tela inicial do Windows 8-->
<meta name="msapplication-TileColor" content="#2e3186">
<meta name="msapplication-TileImage" content="/ms-icon-144x144.png">Nas metas do Windows 8, escohler cor de fundo do bloco (RGB ou Hexadecimal) e a imagem.