As far as I know if you have w32codecs-all, mplayer, the gstreamer010 plugins from Packman, particularly bad, ffmpeg, and ugly, lame, mad, libffmpeg0, you should have been alright. Get all of them from Packman, even if you have to click the Version tab in YaST and choose the specific version manually because it is older, as would be the case if you've upgraded Gnome to GNOME:/STABLE Build Service builds.
Perhaps the gstreamer version of Totem is more crippled than I had thought, but I have seen users report all being well as long as they had installed the Packman versions of the plugins.
If you like you can install Packman's version of totem and totem-plugin, which will bring in the xine version of Totem and would also have brought in libxine1 as a dependency, and will automatically uninstall xine-lib, the default xine plugin in OpenSUSE that excludes playback of proprietary codecs.
I don't know why so many now recommend the installation of the libdvdcss from the vlc player's repo. That is the version that needs a libxine1 enabled player for encrypted dvd's. The libdvdcss2, from the libdvdcss repo of the vlc ftp site will enable decryption on any dvd capable player, gstreamer or xine based. I still have that saved, but it is downloadable from the site, you make it executable and right-click Install With Yast, logout and in and you've got dvd. Some players may still need libdvdnav4 and libdvdplay but most get along fine with only libdvdread3 that gets installed as a dependency with the players.
If you did the single cd install you may not have java-sun5-jre, java-sun5-plugin, flash, and realplayer installed but if you switch the Search box to Patterns and select the non-oss multimedia pattern that would take care of that. A further fix for some Java problems is to then upgrade java-sun5-plugin to java-sun6-plugin. That will uninstall java-sun5-plugin and you should then put a check in java-sun6-jre and trash java-sun5-jre before proceeding. Then YaST will complain but tell it it's okay to ignore the non-oss multimedia dependency this time. It will actually remove that check but leave the programs installed.
If you want the Acrobat Reader, you might as well download the newer version from adobe.com. Just make the rpm executable and right click Install With YaST.
It a choice if you want mplayerplug-in, totem-plugin from Packman, or that xine browser plugin mentioned in the sticky. Just don't install more than one of those!
If files aren't opening in RealPlayer you need to rename or delete the interfering codec from /usr/lib/browser-plugins. Totem's Real plugin is named libtotemcomplex something and there are two of those. Mplayer's have real in the name. Ones an .so and ones an .so.xpt. Get rid of those and delete the /home/yourname/.mozilla/firefox/somethingplugins.reg. Run RealPlayer and open the wizard again in the help menu to get its plugin restored properly. Open Firefox and it'll re-register its plugins.
Theoretically just using the one-click Gnome codec installer from the Restricted Formats page of opensuse-community.org should have taken care of at least some of this. The Advanced checkmark in that would have given you the choice of installing some of what I've mentioned automatically. But if you've already started manually installing some of this stuff you may as well try to add the few missing pieces yourself.
See if you've got the stuff I mentioned. If you do, and still can't play your files then something must be broken. You should have no multimedia problems with all that.
I sure hope enough folks get used to this sort of thing. I've typed similar out on enough posts to make my fingers tired!
I just don't feel the guides this time go far enough. And I didn't even talk about the KDE stuff like Amarok (switch it to xine in its settings) and Kaffeine (get 'em from Packman, the rest of the libxine1 plugins, and the needed k3b-codecs Packman plugin!