Steam Controller, an alternative to keyboard/mouse. Though there’s keyboard/mouse ‘trays’ which allow you to use those devices sat on the sofa.
I use Kodi as well as Netflix + MythTV which all runs on one bit of hardware.
Not sure why you’ve had to change hardware, sort out drivers and muck about with the OS / have issues with it. Hardware change could suggest a low-spec initial build.
Sure, it’ll cost a little more to build but you end up with better graphics, no subscription costs for online / multiplayer gaming, cheaper games with online backup of game progress, no optical disc drives or media to worry about and you can build the system to produce very little noise too.
Of course, in saying all of this, if you have a TV and want to play a game every now and again, a console is a much simpler route to go down. However, if you want one box to fulfill numerous duties such as media server, PVR, games console, lounge-based Skype and goodness knows what else, then a PC -based games console can be amazing!
Just to add, in terms of stability, my system has never crashed, never experienced hardware failure or ran in any way abnormally. But, I use Supermicro boards, Xeon CPU’s, ECC ram, Seasonic PSU’s and Noctua coolers.