Definately no fighting
.
I used to be a strong believer in Fedora as a server OS, however it has proven to be not the greatest. I'd say the same for Slackware, and I believe Debian is better for servers, though my experience with it is limited. Personally I don't have much trust in linux anymore, but when I have to use it, I will always choose CentOS.
I've made the turn to FreeBSD as my preference, it is much more stable, secure and reliable in my opinion.