CentOS works well for us. I like the idea of having a free version of a commercial distro (RHEL).
You want something that:
- is seasoned - is widely used - is aggressively updated - is guaranteed to be supported for years - is free
That's your CentOS. It's RHEL, of course. And CentOS has a foundation that gathers cash, so it's not just going to disappear one day.