1 Nginx and PHP-FPM
Nginx is a very efficient web server, and coupled with PHP-FPM seems to be a great way to serve most common dynamic pages, easily connect APC: PHP opcode cache to avoid unnecessary recompilation. Default config for nginx 
2 Memcached + APC
Memcached is an in-memory key-value store for small chunks of arbitrary data (strings, objects) from results of database calls, API calls, or page rendering. The Alternative PHP Cache (APC) is a free and open opcode cache for PHP. No disk cache configuration.
3 Hole-Punching FPC
Depending on your Magento design and configuration of the server we can install the one that best suits you. Speed up your Magento on shared hosting, and get even more on the dedicated! varnish readme