I am a lawyer, and I now practice elder law, so I really should know this (but I don't do wills in my practice). I tried legalzoom. This is the second time I tried a legal doc creation website as a test service for this forum (and our former forum). First, it costs $79 to actually get a copy of the will and there is no way to preview it or read it. So on that front, I think it is a total and absolute waste of money. Second, I had a hard time understanding the questions and knowing what I wanted to answer (true, I went through it in about 3 minutes total, but still, I am a lawyer). So I don't think the average person could really make these decisions with the information given.
I am curious about buying will making software myself, and sometimes on dealmac it was available for less than $10 (although in true cheap fashion, I never pulled the trigger). But my advice here is the same as Elmo: this is an area where you really should pay an attorney to do and to keep track of it. You want it to be right, and when you need it, it is a bit late to fix any mistakes.