Opensuse is an enterprise operating system produced by Novell. It is free (in both senses), fast, and standards-compliant with most of the Standard Linux Base's demands (including .rpm as the package format). I have found that Opensuse is widely applicable and should be better praised, because it works in such a different way than any distro I have used to date. Here is the review.
A whole new world of efficiency
12.2 is fast. And that isn't just a buzzword, it really is fast. Everything from boot to actually using the operating system is just faster than it would be on Ubuntu with a similar setup. One of the reasons for this is the leaving out of certain modules and programs (indexing) that take a big toll on the speed of the system. Also, since it is mostly used for servers Novell cannot afford to have a performance issue, so they trimmed the fat.
Another thing I noticed was incredibly low memory usage. On KDE with Firefox it uses around 500 MiB of RAM. That is extremely small considering that KDE is a beast that is notable for using >1GiB when it feels like it. I'm sure that in an environment like the awesome window manager that number would fall even further.
Repositories and Packages
This is the only area where I was disappointed. In the past small repositories have been a dealbreaker for me, and Opensuse came close. Its repositories aren't nearly as extensive as Ubuntu's or Debian's, or even Sabayon's. For instance, for an edX course a program named Scratch was needed. It was not in the repositories and it was not available as an Opensuse-compatible .rpm, so I have to compile it from the source. That is a large inconvenience. And it has happened before, too. The Awesome window manager isn't even in the repositories, and there is no .rpm package with satisfiable dependencies. That's why I am stuck with KDE for the time being.
The package manager is nice, though. As is the command line version. .rpm grouping (shown above) and pattern searching (command line) are helpful tools to install packages. In fact, pattern searching reduces the needs of pesky meta packages that have been known to cause breakages in systems past.
Opensuse even comes with a program called apper that can install .rpm files, which is much alike what Fedora and Ubuntu do with their respective formats (with software installer and gdebi or the software center)
Opensuse is enterprise. That's all there is to it. If you want a reliable, fast, easily configurable system it is the operating system for you. On the other hand, for a purely desktop-oriented experience it may be a bit too official of a stab at Linux.