[PntSingularity]

Here's a flat-style quote box I made. The colors are adapted for the original vB theme.

<table width="100%" border="0">
<tr><td width="100%" align="center">
<table width="97%" border="0">
  <tr>
    <td width="100%" bgcolor="#738FBF">
      <table width="100%" border="0" bgcolor="#E1E4F2">
        <tr>
          <td width="1%" bgcolor="#738FBF" nowrap align="left" valign="top">
            &nbsp;<font size="1"><b>
            <if condition="$show['username']">
                <phrase 1="$username">$vbphrase[originally_posted_by_x]</phrase>
		<if condition="$postid">
                  <a href="showthread.php?$session[sessionurl]p=$postid#post$postid" rel="nofollow"><img class="inlineimg" src="$stylevar[imgdir_button]/viewpost.gif" border="0" alt="$vbphrase[view_post]" /></a>
                </if>
            <else />
              Quoted Text
            </if>
            </b></font>&nbsp;</td>
          <td width="99%" bgcolor="#E1E4F2">&nbsp;</td>
        </tr>
        <tr>
          <td width="100%" bgcolor="#E1E4F2" colspan="2">
            <table width="100%" cellpadding="2">
              <tr>
                <td width="100%" align="left" valign="top">
                  $message
                </td>
              </tr>
            </table>
          </td>
        </tr>
      </table>
    </td>
  </tr>
</table>
</td></tr>
</table><br />

Click here to see it in action.
If you keep reading through that thread you will find the code to have the very same box as custom bbCode (but with another color scheme). I use the custom one for OOC (Out-of-Character) posts, since it's a roleplaying forum.