AcuDef,
to be honest I'm not sure which one's best though, due to the fact that there's not any BD that I know of with both HD codecs encoded.
What I prefer from Dolby tracks is that the bass is not so overly accentuated (IIRC, all DTS tracks are encoded with a + 3dB over Dolby).
Notwhitstanding that, there are truly gems on DTS, but as I said, I'd like to do a cross-check between both HD codecs, in order to really know which sounds best to my ears though