There are two schools of thought when it come to this sort of thing. The first is start with the best transport/dac you can afford. It is the FIRST piece in the chain, the old garbage in = garbage out school of thought. IMO, a good transport makes all the difference in the worls. Like Nick said, smoooooooooth playback. Although all this high end digital crap still can't compare to a crappy turntable, don't get me started. Case in point, my digital front end costs 3x what my analog front does & still doesn't compare
The other school of though is that you start with your speakers & build your system around them. Not a bad way to go either. Your speakers are the final point of reproduction, if they can't accurately reproduce or at least reproduce in a manner you want to hear then no matter what you do upstream will matter.
Hmmmmmm, I have tried it both ways. I have a stellar transport & DAC, they are very good at what they do but I also have excellent speakers with great cables. Yes, I can hear the difference when I change cables now or tweak my speakers but I have spent some time building the system to where it is today. What I mean by that is that I have spent a lot of time (wasted some time & money too) trying a lot of different gear in my system to get it to sound the way I want. I say this all the time but the most fun in audio for me is experimenting with different gear to see what works with your tastes & system creating a synergy. A new player may be an improvement for you just as new speakers or amp or cables may also be an improvement. Audio is a wonderful hobby, there are so MANY flavors of ice cream out there, you just need to find what works for you. you don't need to spend a lot of money either, buy used. As a matter of fact, buy & sell alot of stuff used, you won't lose much except shipping & it will allow you to see what floats your boat in the audio world.
Or maybe you aren't as much of geek as I am & all you want to do is play music back at home but then again you probably wouldn't be on this site you weren't