Use images instead of radio buttons

Solution 1:

Wrap radio and image in <label>
Hide radio button (Don't use display:none or visibility:hidden since such will impact accessibility)
Target the image next to the hidden radio using Adjacent sibling selector +

/* HIDE RADIO */
[type=radio] { 
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

/* IMAGE STYLES */
[type=radio] + img {
  cursor: pointer;
}

/* CHECKED STYLES */
[type=radio]:checked + img {
  outline: 2px solid #f00;
}

<label>
  <input type="radio" name="test" value="small" checked>
  <img src="http://placehold.it/40x60/0bf/fff&text=A">
</label>

<label>
  <input type="radio" name="test" value="big">
  <img src="http://placehold.it/40x60/b0f/fff&text=B">
</label>

_{Don't forget to add a class to your labels and in CSS use that class instead.}

Custom styles and animations

Here's an advanced version using the <i> element and the :after pseudo:

CSS custom radio and checkbox

body{color:#444;font:100%/1.4 sans-serif;}


/* CUSTOM RADIO & CHECKBOXES
   http://stackoverflow.com/a/17541916/383904 */
.rad,
.ckb{
  cursor: pointer;
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
}
.rad > input,
.ckb > input{ /* HIDE ORG RADIO & CHECKBOX */
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}
/* RADIO & CHECKBOX STYLES */
/* DEFAULT <i> STYLE */
.rad > i,
.ckb > i{ 
  display: inline-block;
  vertical-align: middle;
  width:  16px;
  height: 16px;
  border-radius: 50%;
  transition: 0.2s;
  box-shadow: inset 0 0 0 8px #fff;
  border: 1px solid gray;
  background: gray;
}
/* CHECKBOX OVERWRITE STYLES */
.ckb > i {
  width: 25px;
  border-radius: 3px;
}
.rad:hover > i{ /* HOVER <i> STYLE */
  box-shadow: inset 0 0 0 3px #fff;
  background: gray;
}
.rad > input:checked + i{ /* (RADIO CHECKED) <i> STYLE */
  box-shadow: inset 0 0 0 3px #fff;
  background: orange;
}
/* CHECKBOX */
.ckb > input + i:after{
  content: "";
  display: block;
  height: 12px;
  width:  12px;
  margin: 2px;
  border-radius: inherit;
  transition: inherit;
  background: gray;
}
.ckb > input:checked + i:after{ /* (RADIO CHECKED) <i> STYLE */
  margin-left: 11px;
  background:  orange;
}

<label class="rad">
  <input type="radio" name="rad1" value="a">
  <i></i> Radio 1
</label>
<label class="rad">
  <input type="radio" name="rad1" value="b" checked>
  <i></i> Radio 2
</label>

<br>

<label class="ckb">
  <input type="checkbox" name="ckb1" value="a" checked>
  <i></i> Checkbox 1
</label>
<label class="ckb">
  <input type="checkbox" name="ckb2" value="b">
  <i></i> Checkbox 2
</label>

Solution 2:

Example:

Heads up! This solution is CSS-only.

Credit-card selector, the MasterCard on the modded demo is hovered.

I recommend you take advantage of CSS3 to do that, by hidding the by-default input radio button with CSS3 rules:

.options input{
    margin:0;padding:0;
    -webkit-appearance:none;
       -moz-appearance:none;
            appearance:none;
}

I just make an example a few days ago.

JSFiddle
How to use images for radio-buttons - Gist

Solution 3:

You can use CSS for that.

HTML (only for demo, it is customizable)

<div class="button">
    <input type="radio" name="a" value="a" id="a" />
    <label for="a">a</label>
</div>
<div class="button">
    <input type="radio" name="a" value="b" id="b" />
    <label for="b">b</label>
</div>
<div class="button">
    <input type="radio" name="a" value="c" id="c" />
    <label for="c">c</label>
</div>
...

CSS

input[type="radio"] {
    display: none;
}
input[type="radio"]:checked + label {
    border: 1px solid red;
}

jsFiddle

Solution 4:

Keep radio buttons hidden, and on clicking of images, select them using JavaScript and style your image so that it look like selected. Here is the markup -

<div id="radio-button-wrapper">
    <span class="image-radio">
        <input name="any-name" style="display:none" type="radio"/>
        <img src="...">
    </span>
    <span class="image-radio">
        <input name="any-name" style="display:none" type="radio"/>
        <img src="...">
    </span>
</div>

and JS

 $(".image-radio img").click(function(){
     $(this).prev().attr('checked',true);
 })

CSS

span.image-radio input[type="radio"]:checked + img{
    border:1px solid red;
}