GNU/Linux is good. Without a GUI, it is even more.
I have been, through my different works and roles in organizations, administrator of several different Linux web servers. Beginning with an old Gentoo, I quickly decided that Debian would be the one I would keep as my main server distribution.
I have now been administrating Debian servers (and sometimes a bit of Ubuntu) for 2 years.
From set-up to server migration (who said the user would be glad to keep its IMAP-synchronized emails? Damn the user!) I have been going through a wide range of problems related to GNU/Linux environments.