Here's a quick tip for the Menu control.  I'm pretty sure there were some good reasons why this wasn't the default but I just can't think of them at the moment. [EDIT: I just remembered one of them, this won't work perfectly with ItemSpacing...]

If you want to make the entire cell clickable (and not just the text), try using a style "display:block; width:100%".  You'll only want to apply this to the <A> inside the cells. 

Here's an example:

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
    <style type="text/css">
        .smis a { width:100%; display:block; }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Menu ID="Menu1" runat="server" BackColor="Green" Width="200px">
            <Items>
                <asp:MenuItem Text="ItemA" Value="A"></asp:MenuItem>
                <asp:MenuItem Text="ItemB" Value="B"></asp:MenuItem>
            </Items>
            <StaticHoverStyle BackColor="#FF8080" />
            <StaticMenuItemStyle CssClass="smis" />
        </asp:Menu>
    
    </div>
    </form>
</body>
</html>
 
(ps. Thanks to Pete for helping me figure this out)