CentOS or Fedora.
But, it looks like the Debian camp already has their hooks in you.
Don't give in until you try the RH camp.
CentOS is best, IMHO, because they don't update major versions as quick as Fedora.
I use all 3, have about 50 servers, I'm happy as a pig in fecal matter.
But really, Ubuntu is candy linux. Get some meat and potatoes. Don't be telling Linus you use that sweet-tart of an OS. He'll probably Snicker at you. Either way, you don't have to wait for a PayDay. Sorry, just trying to be a LifeSaver. But I'm probably coming across as more of an AirHead.
For each response, here, you will get a different question.
You may have well as asked "who are you going to vote for, and why".
Mark my words. Each response, different answer.
But, since I know THAT, maybe you'll put me and my 20 years of Linux admining in the "serious considerations" portion of your gray matter. Good luck to you.
Abba Zabba Out!