There's no single answer as there is a list of PROS and CONS for both.
Right off the bat there's a lack of high-resolution games like Starcraft 2 that not only look better at higher resolution but also require a keyboard and mouse to play (and the Steam Controller will never be suitable for many of these).
Controller aside, a 4K HDTV doesn't really help much since it's unlikely you'd be sitting close enough to benefit the same way (I sit about 24" from my 27", 1440p panel). If I sat FOUR FEET from a 48" 4K HDTV then most of the normal video looks like crap, plus it's just too close for the family.
Not that consoles will be gaming in 4K for many, if any titles even with the new ones coming. 4K video yes, 4K games unlikely (though probably a HUD for 4K and that's it).
I'm probably going to buy the XB1 Scorpio for the living room, but will keep my desktop PC for my office.
So...
Both consoles and PC will have a place for a long time to come. If consoles start to offer games meant primarily for a high-res monitor + keyboard/mouse that would change things a lot (maybe hook a 2020 XBox to a 4K gaming monitor) but I think that would CONFUSE the game store so I don't think they'd bother.
*Also, Microsoft wants people to stay on Windows 10. Replacing the need for that by making XBOX a viable replacement will hurt them as some people will start switching to Linux.
I guess a "STEAM MACHINE" is a bit of a hybrid console/PC but then it comes with a PC price tag. It's something to keep an eye on in the future though.
STEAM LINK is a $50 device that allows streaming to an HDTV from your PC. I thought about that, but then I'd have to negotiate my PC usage with when kids want to use the XBOX so that's not feasible either.
GSYNC (NVidia) and Freesync (AMD) can make games a lot SMOOTHER. With some monitors you can average over 100FPS with minimal latency and no screen tear. Even gaming at "only" 40FPS can be a great experience though with Freesync you need at least 2.5X the max/min ratio to work properly (i.e. 30Hz to 75Hz is fine. But 30Hz to 75Hz is bad.).
PC:
- games you can't play on console
- higher quality games (for more expensive hardware)
- asynchronous monitors (GSYNC, Freesync) are awesome and no HDTV has this yet
- VR and other hardware that consoles don't have quite yet
Console:
- hardware cheaper (though games more expensive)
- less hassle to setup and maintain
- 30FPS gaming sucks (some drop under 15FPS at times!)
Summary:
Will there ever be one, best solution?
Not likely. A console would have to offer most everything we get on PC and that's just not likely to happen.