Personally, I love the ease and simplicity of http://www.cgi-factory.com 's e-zine sender. It's fast and easy to use. It also doesn't show advertisements.
Also all the user needs to do for the cgifactory one is to enter their e-mail...with Listbot they enter their e-mail address and then are redirected to another page with more forms to fill. I forget who, but someone estimated that the extra step discouraged about 25% of subscribers.
Who the heck is Gen. Failure and why does he want to read my hard drive?
Soon to come: Aspology.com