Ubuntu and CentOS are both major players in enterprise and data center environments.
There is no denying that both distributions have demonstrated their worth in the server space.
Ubuntu is a strong all-around contender. CentOS is designed with the enterprise in mind in every detail.
If you like the Redhat ecosystem or want an enterprise system with extra long-term support, CentOS is a great choice.
If you prefer the Debian family of distributions and want more flexibility and up-to-date software, Ubuntu is a better choice.
If you want the same distribution on your desktop and server, Ubuntu is a great option.