Best Sounding Computer Audio Player For PC

HQ Player is the obvious consensus answer according to the online comments of the most enthusiastic computer audiophile crowd. The downside is you need a more powerful computer than typical and it is more complex to use than JRiver or similar. Built-in digital EQ is a bonus if you are into that. Many tout it's ability to upsample and convert PCM into quad DSD. Whether or not you can take advantage of it depends on your choice of dad since quad DSD is just coming into common use. 

All that being said, I don't do any of it because I prefer a simpler solution using a NAS and network player(aka single purpose tiny Linux computer made specifically just to run audio) with a tablet-based & phone-based control app. Search microRendu if you care about that whole thing which gets off your topic. Cheers,
Spencer 

@lostbears It's good that your NAS isn't in the same room as your audio system; that's the best place for it. If you can run a long CAT ethernet cable into the listening that is ideal. If not, you can use adapters that plug into AC outlets in both rooms and send the signal from router to audio room where you'd plug a an ethernet cable from the plugged in adapter to the microRendu. Other options include wifi receivers that have ethernet outputs and many brand new routers that come as 3 or more pieces to "spread your router" and wifi signal more evenly thru the house. Anything that has a standard RJ45 ethernet output and you will be in business.
As far as DAC, most are not a problem, and regarding special drivers, you can post on the Sonore Forum on computeraudiophile and Jesus from Sonore( who posts there daily) will address the issue, even working with the manufacturers if they need to write a special compatible driver. For a handful of exotic DACs these issues have already been conquered thanks to other buyers, but most of the time it isn't an issue at all. Ask Jesus telling him about your specific DAC.

Lastly, in my firsthand experience, everything suggested by @uberdine is bettered by a mile with the NAS & microRendu and at a lower cost. I used Mac, A+ in standalone integer mode for years and tested the others mentioned. It was fine and better than most full computer solutions, but the microRendu is in a completely different league and is more intuitive & less buggy in terms of user interface(especially for visitors) and more reliable without library indexing issues, crashes, etc. common to Audirvana+. Cheers,
Spencer

@lostbears Already answered your question about what to do if you can't run an ethernet cable. Search CA for you the popular model of power line adapters that plug into AC outlets in both rooms and send the signal from router to audio room where you'd plug a an ethernet cable from the plugged in adapter to the microRendu. Pretty sure the pair of adapters <$100 via amazon,etc. 
The reason why microRendu doesn't is have multiple outputs is because every cent is engineered into optimizing the sound of its USB output beyond what is on just about every other USB output, including its use of Swenson's Regen tech.
So @lustformusic , when you say that Dac8 (or any other) sounds better with  AES have you tried that vs. USB fed from a microRendu? I would argue that the improvements made probably beat any other source via AES into Dac8. I have no doubt about your assertion using other sources. Cheers,
Spencer

@mwelbourne,
If you've never heard music sound better than from an mp3, you need to get out of the house more or just invest in something better. Storage is getting pretty cheap, no reason not to store larger better sounding file formats. Ripped redbook CDs from your local library will be a big improvement. Good high rez files usually even more so. 

@lostbears So what have done since 2016 on the topics discussed? Cheers,
Spencer

It's XX High End, a software package, from Phasure. It's got a small fanatical user base. 
It's a windows tweaker's paradise, but I find it far from user friendly. The last thing I want to do is change settings and control my playback from a computer keyboard. But if the idea of changing varying digital filters while you listen sounds appealing, then you might enjoy it. Different horses for courses...Cheers,
SPencer