Started with Mandrake a long time ago and when it went away turned to Ubuntu and have stuck with it ever since. Surprised no one mentioned LTS (long time support) which I think is 5 years. This means for servers you don’t have to worry about frequent upgrades (think fedora) and for desktops my setup stays stable for a good while.

I try other disros in VMs just to try sexier stuff but for production stick to Ubuntu.