Odoo 10 will run equally well on both platforms, however I would recommend ubuntu 16 if you are running the odoo instance locally on your machine or on your LAN, because it has excellent online support and discussion forums for troubleshooting in case you run into some trouble.

But if your odoo instance is going to be hosted on a VPS then Cent OS 7 will be a better choice because of its reputation for being relatively stable and secure.