Is Ancestry.com the only Online Genealogy Service?

As my subject asks is Ancestry the only genealogy site worth joining. The few others I have found are:

MyHeritage.com
Archives.com
Genealogy.com
FamilySearch.org

I have seen plenty of TV ads for Ancestry and I have heard it has gotten better with the new website but I wanted to get some opinions before I invest any dollars. I assume moving your family tree information from one service to another would be a huge headache if I ever wanted to change services.

I had issues with Ancestry.com. I do not recommend them as their website seems really slow and my browser constantly hangs. Bad Bad Bad