I have the same version of Ubuntu. You don't uninstall completely by deleting files. How did you install this Realplayer?
If your problem is in viewing video and audio from internet web pages, those files are associated with plugins and are changed in the browser options. If a plugin will not be removed, you can at least disable it in the browser. The rest of this has nothing to do with browser plugins.
There is an explanation of where and how file associations are stored in Ubuntu here:
Also see this as a possible fix:
If you use the Ubuntu Tweak (which I haven't tried), you probably won't need the directions below. It might be the best thing to do.
The thing that might be wrong with your file associations is that Realplayer has made itself the default for all your video file types and maybe some audio file types. The only good way to uninstall an application is through the synaptic package manager, but it only uninstalls .deb packages. Sometimes a file association problem as you describe can be fixed by manually editing a "defaults.list" file in those cases to change that.
Enter these commands in the Terminal program and leave the Terminal window open until you are finished editing the defaults.list file:
Now make a copy of the defaults .list file and rename the copy to save it if you need to restore it later:
cp -i defaults.list defaults.list.old
Open the defaults.list for editing:
gksudo gedit defaults.list
Then enter your password at the prompt. This opens the list of default file-type associations.
In the list of default file-type associations for video or audio find all references to realplayer.desktop or helix.desktop to the right of the "=" and change them to mplayer.desktop, or vlc.desktop, or whatever you need. I use smplayer, but my "defaults.list" says "totem.desktop".
If you set most of your video types to "totem.desktop", you can hopefully sucessfully choose mplayer later by right-click choosing an application without realplayer taking over again. If you don't see a problem here, make no changes. When you are through, save the file if it was changed.
Here is a copy of only the relevant parts of my defaults.list file for your reference. The only thing I changed since install is the vlc player for DVD's. Take note of the entries for realaudio and realvideo also: