They tackle the initial requirements and help a lot in building a WordPress site / blog.
So, here is the list with some info for each one of them
– All in One SEO (In a few words, it integrates your WordPress site /blog with SEO)
– Akismet (Spam filter for WordPress comments)
– WPtouch (Gives your WordPress site / blog the mobile appeal. Just think of how many users reach you via smartphones, mobile phones nowadays)
– Editor Extender (Enhances your WordPress editor)
– WordPress.com Stats (Provides statistics for your WordPress site /blog)