I run Fedora on one of my regular desktops. For the most part, Fedora has been pretty solid since version 20, and knowing that it uses a lot of bleeding edge technology I try not to complain about it. Since version 22, however, I noticed a horrible memory leak in Gnome's Tracker software that has been killing my desktop every day.
For those unaware, Tracker is a search engine, a search tool, and a metadata storage system found in the Gnome 3 desktop environment. It's kind of handy, but when it fills up 24GB of RAM and then crashes your box at least once a day, it's time to call it in.
The simple fix is to turn off the Tracker store and all of the miners. This should free up your lost RAM immediately and stop your system from crashing regularly.
$ tracker control -r
Once done, you can verify the status of Tracker:
$ tracker control -S
That's all there is to it. Hopefully this will be fixed in a future Gnome (I am currently running Fedora 23 with Gnome 3.18 and the issue is still present.)