all of plugin in wp is good, not best; but it depend on your needs. If you want to make sitemap, google sitemap xml plugin is one option; if there is a new developer of google site map, it perhaps is not the best anymore.., etc
To me, google sitemap plugin is my most important plugin, if i have to disable other, i will, but not google sitemap.xml generator Here is a video how you set up sitemap.xml properly.
I'm using Google XML Sitemap Generator for WordPress and it is really good. It's very useful because you don't have to worry about telling Google you updated your site everytime you write a new post.
Google Sitemap XML generator, so far the best - I haven't had any issues except for a buggy server which didn't like it using 60mb... Great plugin, gets good spider traffic back
I installed dagon sitemap generator but no sitemap was generated, so i reinstalled google sitemap xml. I was not able to install it, at first. You can also install the same version of this plugin but with translator addition.
I am using Google XML SiteMaps plugin as well and have been for two years on all of my 5 blogs I administrate.
The Dagon Sitemap Generator Plugin generates HTML sitemaps. Here is a nice blog entry, which describes the installation and usage of that plugin: http://www.jaycjayc.com/ddsitemap-generator-plugin/. I am using both Google XML SiteMaps plugin and Dagon Sitemap Generator Plugin. The Google XML SiteMaps plugin generates and XML sitemap for Google (this sitemap contains also an url address of the HTML sitemap). I am using the Dagon Sitemap Generator to generate HTML sitemap for my users and also for Google.