I've setup a directory on my Mac which has a vanilla Wordpress download, with about five basic themes and the following plugins:
Akismet - Spam prevention workhorse
bsuite - for quick stats
Head meta description - already mentioned
Optimal title - rearranges post name in front of blog title
Related posts - returns related posts for the current entry shown
Sociable - Puts buttons for favorite social media sites at the end of post
Simple Tags - Easy way to add hahahahahahahahahaha tags to your post
Google Sitemaps