If you aren't gaming or doing anything remotely demanding that would require a powerful desktop then there's no point having a desktop at all. It's just a big tower that needs a desk, keyboard, monitor etc that can't be packed away down the side of the sofa.
If you want to game in the living room on a PC then how about a nice ITX case that won't look out of place and play in big picture mode with a wireless Xbox controller and a wireless keyboard for games that need them. You can still put them away in a drawer when your gaming is over.
I played like this for 3 years until I moved house and got ab extra room for my PC. I found that with my phone and tablet that things like surfing the web, YouTube, emails could all be handled without the PC and the PC was exclusively for gaming