W3 Total Cache - Takes care of minification problems, caching and speeds up your site dramatically.
All In ONE SEO - Includes a sitemap.
The only 2 plugins I run and get 95/95+ (without calls to Google Adsense, which you're penalized for...), but I am on a dedicated server with other stuff in the background helping out (tossing cached pages in RAM, etc.).
Note: I took out all the bloat W3 adds to the .htaccess file and edited my httpd.conf file as .htaccess files will slow down a site running on Apache.
Per domain, I add custom URL rewrites for permalinks, etc. I have no .htaccess files for WordPress installations.