Well, since you posted here, and I'm a Debian nut, I'll say go with Debian. It may not have the prettiest installer but it's not worse than OpenBSD.
FreeBSD, OpenBSD, NetBSD and so on are *not* Linux distributions. Linux is the kernel that makes Linux Linux, while the *BSD systems have their own kernels. Most of these open Unix-like systems (both Linux and BSD ones) are more or less based on the GNU operating system
and are pretty similar in appearance and functionality. The GNU OS is a free (free as in freedom) set of commands most people assume will be available on a Unix-like system. Linux would probably not have been very successful if there wasn't already an OS (without a kernel) to match the kernel with in order to produce a usable system. The opposite is also true - the GNU project has benefited vastly from the success of Linux, so they both support each other.
However, in order to further confuse you I have to mention there is a Debian GNU/FreeBSD project, where the Linux kernel is replaced by the FreeBSD kernel and all packages recompiled and updated to work with FreeBSD instead of Linux, with Debian's superior package management still in place. There is also Debian GNU/Hurd.