简单粗暴，耗费资源

* { padding: 0; margin: 0; border: 0; }

雅虎工程师提供的CSS初始化示例代码

body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,button,textarea,p,blockquote,th,td { margin:0; padding:0; }
body { background:#fff; color:#555; font-size:14px; font-family: Verdana, Arial, Helvetica, sans-serif; }
td,th,caption { font-size:14px; }
h1, h2, h3, h4, h5, h6 { font-weight:normal; font-size:100%; }
address, caption, cite, code, dfn, em, strong, th, var { font-style:normal; font-weight:normal;}
a { color:#555; text-decoration:none; }
a:hover { text-decoration:underline; }
img { border:none; }
ol,ul,li { list-style:none; }
input, textarea, select, button { font:14px Verdana,Helvetica,Arial,sans-serif; }
table { border-collapse:collapse; }
html {overflow-y: scroll;} 

.clearfix:after {content: "."; display: block; height:0; clear:both; visibility: hidden;}
.clearfix { *zoom:1; }

腾讯官网 样式初始化

body,ol,ul,h1,h2,h3,h4,h5,h6,p,th,td,dl,dd,form,fieldset,legend,input,textarea,select{margin:0;padding:0} 
body{font:12px"宋体","Arial Narrow",HELVETICA;background:#fff;-webkit-text-size-adjust:100%;} 
a{color:#2d374b;text-decoration:none} 
a:hover{color:#cd0200;text-decoration:underline} 
em{font-style:normal} 
li{list-style:none} 
img{border:0;vertical-align:middle} 
table{border-collapse:collapse;border-spacing:0} 
p{word-wrap:break-word}

新浪官网 样式初始化

body,ul,ol,li,p,h1,h2,h3,h4,h5,h6,form,fieldset,table,td,img,div{margin:0;padding:0;border:0;} 
body{background:#fff;color:#333;font-size:12px; margin-top:5px;font-family:"SimSun","宋体","Arial Narrow";} 

ul,ol{list-style-type:none;} 
select,input,img,select{vertical-align:middle;} 

a{text-decoration:none;} 
a:link{color:#009;} 
a:visited{color:#800080;} 
a:hover,a:active,a:focus{color:#c00;text-decoration:underline;}

淘宝官网 样式初始化

body, h1, h2, h3, h4, h5, h6, hr, p, blockquote, dl, dt, dd, ul, ol, li, pre, form, fieldset, legend, button, input, textarea, th, td { margin:0; padding:0; } 
body, button, input, select, textarea { font:12px/1.5tahoma, arial, \5b8b\4f53; } 
h1, h2, h3, h4, h5, h6{ font-size:100%; } 
address, cite, dfn, em, var { font-style:normal; } 
code, kbd, pre, samp { font-family:couriernew, courier, monospace; } 
small{ font-size:12px; } 
ul, ol { list-style:none; } 
a { text-decoration:none; } 
a:hover { text-decoration:underline; } 
sup { vertical-align:text-top; } 
sub{ vertical-align:text-bottom; } 
legend { color:#000; } 
fieldset, img { border:0; } 
button, input, select, textarea { font-size:100%; } 
table { border-collapse:collapse; border-spacing:0; }

网易官网 样式初始化

html {overflow-y:scroll;} 
body {margin:0; padding:29px00; font:12px"\5B8B\4F53",sans-serif;background:#ffffff;} 
div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,form,fieldset,input,textarea,blockquote,p{padding:0; margin:0;} 
table,td,tr,th{font-size:12px;} 
li{list-style-type:none;} 
img{vertical-align:top;border:0;} 
ol,ul {list-style:none;} 
h1,h2,h3,h4,h5,h6{font-size:12px; font-weight:normal;} 
address,cite,code,em,th {font-weight:normal; font-style:normal;}

博客园 样式初始化

html,body{color:#000;background:#FFF;}
body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,button,textarea,p,blockquote,th,td{
    margin:0;padding:0;
}
table{border-collapse:collapse;border-spacing:0;}
fieldset,img{border:0;}
address,caption,cite,code,dfn,em,strong,th,var,optgroup{
    font-style:inherit;font-weight:inherit;
}
del,ins{text-decoration:none;}
li{list-style:none;}
caption,th{text-align:left;}
h1,h2,h3,h4,h5,h6{    font-size:100%;font-weight:normal;}
q:before,q:after{content:'';}
abbr,acronym{border:0;font-variant:normal;}
sup{vertical-align:baseline;}
sub{vertical-align:baseline;}
legend{color:#000;}
input,button,textarea,select,optgroup,option{
    font-family:inherit;font-size:inherit;font-style:inherit;font-weight:inherit;
}
input,button,textarea,select{*font-size:100%;}
.clear{clear:both;}
input::-moz-focus-inner{ border: 0;padding: 0;}

/*added*/
input[type=button],input[type=submit] {-webkit-appearance: button;}

选择性初始化举例（综合）

body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,legend,button
form,fieldset,input,textarea,p,blockquote,th,td {   
　　padding: 0;   
　　margin: 0;   
}
/* 酌情修改 */
body {
    background:#fff;color:#333;font-size:12px; margin-top:5px;font-family:"SimSun","宋体","Arial Narrow";
}

/* 短引用的内容可取值：''或"" */
q:before,q:after {content:”;}  

/* 缩写，图片等无边框 */
fieldset,img,abbr,acronym {border: 0 none;}
abbr,acronym {font-variant: normal;}
legend {color:#000;}

/* 清除特殊标记的字体和字号 */
address,caption,cite,code,dfn,em,strong,th,var {   
　　font-weight: normal;   
　　font-style: normal;   
}

/* 上下标 */
sup {vertical-align: text-top;}
sub {vertical-align: text-bottom;}

/* 设置表格的边框被合并为一个单一的边框, 指定分隔边框模型中单元格边界之间的距离为0*/
table {   
　　border-collapse: collapse;   
　　border-spacing: 0;   
}   

/* 表格标题及内容居左显示 */
caption,th {text-align: left;}
input,img,select {vertical-align:middle;}

/* 清除列表样式 */
ol,ul {list-style: none;}  

/* 输入控件字体 */
input,button,textarea,select,optgroup,option {
    font-family:inherit;
    font-size:inherit;
    font-style:inherit;
    font-weight:inherit;
}

/* 标题元素样式清除 */ 
h1,h2,h3,h4,h5,h6 {   
　　font-weight: normal;   
　　font-size: 100%;   
}   

/* 链接样式，颜色可酌情修改 */
del,ins,a {text-decoration:none;}
a:link {color:#009;}
a:visited {color:#800080;}
a:hover,a:active,a:focus {color:#c00; text-decoration:underline;} 

/* 鼠标样式 */
input[type="submit"] {cursor: pointer;}
button {cursor: pointer;}
input::-moz-focus-inner { border: 0; padding: 0;}

.clear {clear:both;}

我的

blockquote,
body,
button,
dd,
div,
dl,
dt,
form,
h1,
h2,
h3,
h4,
h5,
h6,
input,
li,
ol,
p,
pre,
td,
textarea,
th,
ul {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none !important;
    margin: 0;
}
input[type="number"] {
    -moz-appearance: textfield;
}
::-webkit-scrollbar {
    width: 5px;
    height: 5px;
}
::-webkit-scrollbar-thumb {
    border-radius: 2.5px;
    box-shadow: inset 0 0 5px rgba(0, 0, 0, 0.2);
    background: rgba(0, 0, 0, 0.2);
    opacity: 0.7;
}
::-webkit-scrollbar-track {
    border-radius: 0;
    box-shadow: inset 0 0 5px rgba(0, 0, 0, 0.2);
    background: #f5f5f5;
}

button,
input,
select,
textarea {
    font-family: inherit;
}

/*其他*/
.tx-center {
    text-align: center;
}
.tx-right {
    text-align: right;
}
.fl-right {
    float: right;
}
.cl-theme {
    color: $theme-color !important;
}
.cl-warning {
    color: $theme-color-warning;
}
.cl-danger {
    color: $theme-color-danger;
}
.cl-big-gray {
    color: $theme-color-big-gray;
}
.cl-gray {
    color: $theme-color-gray;
}
.tx-row1 {
    text-overflow: ellipsis;
    white-space: nowrap;
    overflow: hidden;
}