WebForms are going to be the heaviest in most cases. ASP.Net MVC is quite lightweight and surprisingly fast compared to WebForms.
Building an application using HttpHandlers to serve pages may be fast when serving static content, but if you plan to use some sort of templating to serve dynamic data, you're going to cause yourself a lot of undue work. As for performance, it's hard to say with this option because your templating could be nasty or possibly not.