Most of the time I come up with a problem, eg "how do I draw a picture in ubuntu?" and then after some googling I come up with a solution eg "get gimp installed" But what if I'm not looking for anything in particular? I just want to browse randomly. I know of the software center, but maybe I'm not using it correctly. Is there a way to make IT display a simple list of every possible app? Is there some web page with them all on it?
The apps website will show you everything Ubuntu Software Center has with the same categories. All of the below options will generally show you the same results with a 1 line description. You will have a better search if you first decide what category you search fits into though.
From USC ...
The 1 line description often is enough to get a basic idea of what the software is about.
And from the apps website:
You can also install the old synaptic (that was software we used to use before USC) with
sudo apt-get install synaptic
The "all" option will list everything, even software that is not in itself is useable on the desktop (like command line utilities or tools software depends on).
And we also have a website you can search packages.ubuntu.com for every available release:
From all of these I do believe the Ubuntu Software Center is the best option if you have your system at hand. If you do not (because you are working on a Windows machine the apps website is a good 2nd option. The synaptic and the packages website method tend to show alot of packages that have no purpose themself but are there to support desktop/server software.