Best Options to add a contact form to website?

if your site supports php try this:
just edit the required fields (the config section)

<table width="760" border="0" cellspacing="10" cellpadding="0" align="center">
<tr>
<td align="center">

<?php
if (isset($_POST["op"]) && ($_POST["op"]=="send")) {

/******** START OF CONFIG SECTION *******/
$sendto = "";
$subject = "Website Contact Enquiry";
// Select if you want to check form for standard spam text
$SpamCheck = "Y"; // Y or N
$SpamReplaceText = "*content removed*";
// Error message prited if spam form attack found
$SpamErrorMessage = "<p align=\"center\"><font color=\"red\">Malicious code content detected.
</font><br><b>Your IP Number of <b>".getenv("REMOTE_ADDR")."</b> has been logged.</b></p>";
/******** END OF CONFIG SECTION *******/


$name = $HTTP_POST_VARS['name'];
$email = $HTTP_POST_VARS['email'];
$message = $HTTP_POST_VARS['message'];
$headers = "From: $email\n";
$headers . "MIME-Version: 1.0\n"
. "Content-Transfer-Encoding: 7bit\n"
. "Content-type: text/html; charset = \"iso-8859-1\";\n\n";
if ($SpamCheck == "Y") {
// Check for Website URL's in the form input boxes as if we block website URLs from the form,
// then this will stop the spammers wastignt ime sending emails
if (preg_match("/http/i", "$name")) {echo "$SpamErrorMessage"; exit();}
if (preg_match("/http/i", "$email")) {echo "$SpamErrorMessage"; exit();}
if (preg_match("/http/i", "$message")) {echo "$SpamErrorMessage"; exit();}

// Patterm match search to strip out the invalid charcaters, this prevents the mail injection spammer
$pattern = '/(;|\||`|>|<|&|^|"|'."\n|\r|'".'|{|}|[|]|\)|\()/i'; // build the pattern match string

$name = preg_replace($pattern, "", $name);
$email = preg_replace($pattern, "", $email);
$message = preg_replace($pattern, "", $message);

// Check for the injected headers from the spammer attempt
// This will replace the injection attempt text with the string you have set in the above config section
$find = array("/bcc\:/i","/Content\-Type\:/i","/cc\:/i","/to\:/i");
$email = preg_replace($find, "$SpamReplaceText", $email);
$name = preg_replace($find, "$SpamReplaceText", $name);
$message = preg_replace($find, "$SpamReplaceText", $message);

// Check to see if the fields contain any content we want to ban
if(stristr($name, $SpamReplaceText) !== FALSE) {echo "$SpamErrorMessage"; exit();}
if(stristr($message, $SpamReplaceText) !== FALSE) {echo "$SpamErrorMessage"; exit();}

// Do a check on the send email and subject text
if(stristr($sendto, $SpamReplaceText) !== FALSE) {echo "$SpamErrorMessage"; exit();}
if(stristr($subject, $SpamReplaceText) !== FALSE) {echo "$SpamErrorMessage"; exit();}
}
// Build the email body text
$emailcontent = "
-----------------------------------------------------------------------------
WEBSITE CONTACT ENQUIRY
-----------------------------------------------------------------------------

Name: $name
Email: $email
Message: $message

_______________________________________
End of Email
";
// Check the email address enmtered matches the standard email address format
if (!eregi("^[A-Z0-9._%-]+@[A-Z0-9._%-]+\.[A-Z]{2,6}$", $email)) {
echo "<p>It appears you entered an invalid email address</p><p><a href='javascript: history.go(-1)'>Click here to go

back</a>.</p>";
}

elseif (!trim($name)) {
echo "<p>Please go back and enter a Name</p><p><a href='javascript: history.go(-1)'>Click here to go back</a>.</p>";
}


elseif (!trim($message)) {
echo "<p>Please go back and type a Message</p><p><a href='javascript: history.go(-1)'>Click here to go back</a>.</p>";
}

elseif (!trim($email)) {
echo "<p>Please go back and enter an Email</p><p><a href='javascript: history.go(-1)'>Click here to go back</a>.</p>";
}

// Sends out the email or will output the error message
elseif (mail($sendto, $subject, $emailcontent, $headers)) {
echo "<br><br><p><b>Thank You $name</b></p><p>We will be in touch as soon as possible.</p>";

}
}
else {
?>
<p align="center">Please complete all details of your enquiry<br>and we will get back to you shortly.</p>
<br>
<form method="post"><INPUT NAME="op" TYPE="hidden" VALUE="send">
<table>
<tr>
<td><p>Name:</p></td>
<td>
<input name="name" type="text" size="30" maxlength="150">
</td>
</tr>
<tr>
<td><p>E-mail:</p></td>
<td>
<input name="email" type="text" size="30" maxlength="150">
</td>
</tr>

<tr>
<td valign="top"><p>Message:</p></td>
<td><textarea name="message" cols="40" rows="6"></textarea></td>
</tr>
<tr><td></td> <td><input name="submit" type="submit" value="Send Message"></td></tr>
</table>
</form>
<?php } ?>

</font></td>
</tr>
</table>