I'l try to avoid the 'lets bash OS X' thing (several puns in there - none intended)...
I've seen linux crash a lot. I've seen NT crash a lot. Both suck. Mind you, in university, our Unix servers crashed too...
IMHO, Mandrake kicks. Redhat is far less nice to you. And for interfaces, Enlightenment is really nice to work with. Mandrake has tons.
Linux is NOT a serious server. It is for web based stuff, and not much more. Mission critical systems are done on serious computers that are NOT x86. HP-UX, AIX, AS400, etc. are the standards for real computing power, until you need something completely insane like a Cray.
That should change in the future IF hardware improves. 99% of all my crashes are either from crappy software running and doing bad things, or from crappy hardware doing likewise. It is 'usually' not the fault of the OS. (I've had more crashes on fresh installations of linux than windows, but those were probably hardware related.)
Like MorningZ said - Mandrake - highly recommended.
My next box will be a Mandrake box. I just finished trying out Redhat 9, and didn't really like it that much. That box has Windows 2000 Server on it now...