I use redhat enterprise linux on all of my servers

freebsd 4.x or 5.x on the servers
apache for webserver
gentoo for mysql server and desktops.

However... MySQL performs faster on Linux, so I usually go with Linux for a dedicated database server... For web though, there's no comparison.

FreeBSD Apache qmail

Not one Linux server in the top 50 longest uptime servers on the Internet:
http://uptime.netcraft.com/up/today/top.avg.html

Yep correct answer in my opinion for a money making venture - pay a few $ - its worth it. Sure technically freebsd may be better, but who gives a shit? A mac might be better than xp too, but it ends up being harder to use because fewer programs are available.

I use Red Hat Enterprise Linux in about 35 servers - all updated and patched with one command (including kernel) and takes 1/2 a person maintain all 35. I could really give a flying fuck if something besides RHEL is slightly faster.

And Last I heard freebsd doesn't even have iptables, i can't afford (and don't want) hardware firewalls on remote servers. This issue alone seals the deal for me.

yes there is iptables for freebsd its called IPFW

Has freebsd resolved its SMP problems yet? That was a 100% deal-killer for me a couple years ago.

FreeBSD all the way!

We used to be on Linux and while it worked we had lots of problems

Switched to FreeBSD and smooth sailing for over 2 years now.

More programmers around that know Linux and they are often cheaper than FreeBSD programmers but hey you get what you pay for.

FreeBSD its hard to ever go back to not having ports

They're both great. Which one you chose just depends which you're the most comfortable with. FreeBSD 5.x has some great improvements over 4.x which gives it a slight edge in my book overall. I'm more comfortable using Linux though, since I've used it for years now, so that is what I'd put on my own systems.