This was a gag on The Big Bang Theory a while ago, but all the same I realised that I didn’t really know myself which was better so decided to do some digging.
Referenced from BigBangTrans:
Leonard: Alicia, what do you want as your default setting for DVDs, 5.1 Dolby or DTS?
Alicia: Whatever you think is best, cutie.
Leonard: Well, DTS has more low end, so… okay
By default our Marantz surround sound receiver has both, but we tend to play using Dolby Digital in Movie mode. And to tell the truth it does sound fine to my ears.. but that doesn’t necessarily mean it’s the best.
Now, rather than rewrite the wheel I’m going to reference HowToGeek:
https://www.howtogeek.com/304200/whats-the-difference-between-dolby-digital-and-dts-and-should-i-care/ – they have done a good job in explaining what’s what in as simple way as possible.
One thing to note is that “Higher bitrate does not necessarily mean higher quality” and whether one sounds better than another is also questionable.
At the end of the day, you’re better off testing yourself or letting your AV receiver choose for you 🙂