In hopes this will not start a full scale debate, I am currently working on a WordPress configuration template, not theme but a pre-configured boilerplate/distribution from which to clone other sites, to give away to newbies. My primary goal is to include the best plugin for each job but to also save them configuration time.
Since function defines form, the intended sites are Amazon Minisites for people trying to make a little extra money in these hard economic times. I have already had the following recommendations:
simple google sitemap
wordpress database backup
However, I believe that I have already found major improvement with the following:
fast secure contact forms
google xml sitemaps
w3 total cache (I too am having a devil of a time configuring this little bugger)
I also found a list of recommendations by Yoast and hope someone could narrow it down for me to help others.