ABC's Nightline has the plate-list and the play-list, Arno's Art has the app-list. I fling and sling a lot of terms but what is on my machine. My main machine is a HP Pavilion a1030e, not a powerhouse by any stretch of the imagination. I won't detail it, it is a middle of the road typical desktop. I have Kubuntu installed, that's Ubuntu Linux with the KDE desktop GUI.
Firefox is my main web browser.
Konqueruor my second web browser is also a file manager, viewer, etc, etc, etc, swiss army knife.
Open Office is a complete office suite, does MS file formats except MS macro stuff.
eSword is a Bible study center with multiple translations, commentaries, maps, etc; totally wonderful and you can get multiple languages too, including Arabic.
GIMP, the GNU Image Manipulation Program is raster graphics like Photoshop.
Inkscape, is vector graphics like Adobe Illustrator.
Blender 3D is 3D graphics and animation, like no other!
Gwenview is a picture viewer.
Scribus is a desktop publisher system.
Amarok is a audio player and management system.
VLC, VideoLan Controller is the absolute best play anything media player, it streams and captures stills, records and makes Julian fries.
Kb3 is the KDE CD/DVD copy/burner software, does a great job.
Dolphin is a file manager with previews, kills the need for desktop shortcuts, the refrigerator door magnet look is over.
Basket Note Pads is a note pad that handles pictures and text. It is better than a mind map.
Kmail is my email handler.
Synaptic is how you access Linux repositories to install and remove software. It also finds and installs required libraries and extra stuff needed to run software you chosen.
These are the main stuffs on my PC, not nearly a third counting all the small apps like calculators and screenshot apps. OK, I did't mention games. I have lots of games, but I am not a gamer. For the most part Linux does not have Microsoft PC games, Xbox games, Nintendo games, Wii games, Mac games or Play Station Games, so get over it. It does have it's own array of games that might or might not be sort of like those games or not. Not being a game connoisseur, I can not say, but Linux is not lacking in games, if you want Linux games.
I just do what I do on my PC and I am sure others do differently. I can not cover the full breath of what Linux users can do. But you have the liberty to explore, to check it out, to roam like a free range chicken and go to the outer limits or just check your email and play solitaire. Now, you can get all this glorious wonder for free, the cost of download time or the cost of purchase of a CD/DVD is minor. This leaves a hollow feeling in many, so I encourage you, if you are so inclined, to donate to the various software projects of the software you accumulate to help continue development, upgrades and availability. You can also put in your 2 cents by offering suggestions and reporting bugs to these projects. It's a community thing.