GoAccess is a real-time Web log analyzer and interactive viewer for almost every Web server. It runs in a terminal and provides fast and valuable HTTP statistics for system administrators that require log monitoring and visual reports on the fly. GoAccess can monitor unique visitors, browsers, spiders, OS, hosts and IP geolocation, keyphrases, referring sites, status codes, etc. It has support for IPv6 and it parses nearly any Web log format.
Definitely useful when it comes to analyze web server statistics interactively and without having to generate huge reports.