back up to dropbox

Hello,
I want to back up my site to dropbox, but not create a large size back up. Just want to be able to re-install from back up.
Presented with list of files below: which ones are necessary, and which are not?
Thank you.
cgi-bin images wp-admin wp-content wp-includes _private .htaccess _vti_bin _vti_adm _vti_aut, .htaccess _vti_cnf _vti_log _vti_pvt _vti_txt .htaccess error_log index.php license.txt postinfo.html readme.html sitemap-image.xml sitemap.xml sitemap.xml.gz wp-activate.php wp-app.php wp-atom.php wp-blog-header.php wp-comments-post.php wp-commentsrss2.php wp-config-sample.php wp-config.php wp-cron.php wp-feed.php wp-links-opml.php wp-load.php wp-login.php wp-mail.php wp-pass.php wp-rdf.php wp-register.php wp-rss.php wp-rss2.php wp-settings.php wp-signup.php wp-trackback.php xmlrpc.php _vti_inf.html