Debian, by a large margin. Ubuntu is already "owned" by Canonical and openSUSE is just a free counterpart to SUSE Linux Enterprise by SUSE software solutions Gm

Debian, by a large margin. Ubuntu is already "owned" by Canonical and openSUSE is just a free counterpart to SUSE Linux Enterprise by SUSE software solutions GmbH in very much the same way CentOS was to RHEL in the recent years.