suse and debian are good distros, they're basically sugarcoated versions of unix. i don't find linux as reliable as unix though, the only time i use it is if i need weird drivers or something.

personally i think freebsd is the best os out there (except maybe mac osX). we use netbsd at work for print servers, but i'm not very impressed with it, my experience is that it's much slower then free/openbsd. but with enough effort you can make linux run as good as unix and vice versa, it's all about what you're comfortable with.

ps -- http://bsdforums.com/forums is an excellent reference