Start out with the basics – Apache, MySQL and PHP + extensions
apt-get install mysql-server mysql-client apache2 php5 php5-cli libapache2-mod-php5 php5-mysql php5-curl php5-gd php-pear php5-imagick php5-mcrypt php5-memcache php5-mhash php5-sqlite php5-xmlrpc php5-xsl php5-json php5-dev libpcre3-dev
I recommend using this on Debian Jessie. That way you get a bleeding edge version of PHP (5.5.8 as of right now)
OpCode cache and APCu (Optional)
pecl install ZendOpcache-beta
pecl install apcu-beta
Add the following to /etc/php5/apache2/php.ini
zend_extension=opcache.so
extension=apcu.so
Configure Opcache by adding this to /etc/php5/apache2/php.ini
opcache.max_accelerated_files=30000
opcache.memory_consumption=160
opcache.revalidate_freq=0
Restart apache. The extensions should be available and configured. (You can verify this via phpinfo(); )
Useful tools (Optional)
apt-get install htop vim