The best replacement for apache2 is httpd.

The best alternatives to apache2 are rated as following:
★★★★★  httpd
★★★★  lighttpd
★★★★  apache
★★★  nginx
★  apache 1
  apache tomcat
  apache1

Your alternative for apache2 is not listed? Suggest!
Speaking about apache2, one probably shouldn't forget about virtual host.

Other search terms related to apache2 and their ratings are:
★★★★★ virtual host
★★★ php5
You have in mind a companion for apache2 and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of apache2 in all years. Click on graph for more.
apache2
httpd
lighttpd