What DAC upgrade made you say “DAMN, that sounds SO MUCH better than my last DAC”?

Without a doubt the Bricasti M3 dac with streamer board option 
is a incredible price ,performance leader . I had a Denafrips Venus 
and was going to go with a Terminator ,or a Holo springs Kte
 but Anthony at Perrotta Consultants ,on theEast coast IMO a premiere dealer with a great assortment of great gear said these other Chinese dacs are very good But Bricasti are known for their musicality in the mastering studios  but expensive.this M3 
Uses the classic  Analog Devises 1955 laser trimmed Multibit dac chips , and tons of trickle down technologies, fantastic build quality and execution and the streamer is seamless and Roon ready ,and best of 2020  it truly delivers excellent detail and realism,it sounds like a mixture of tubes and solid state and if you buy a cable or power cord ,very attractive package pricing .
https://m.youtube.com/watch?v=pG1TGrVEpOc

Each step in my audio journey has seemed to be a great improvement...from my Marantz receiver to a Wyred for Sound DAC, then to a BMC DAC/Pre, then to my current Bricasti M1 Limited Gold. 

Helping along the way were changes in the source as well. From a Marantz CD player, to a BMC BDCD, to a Laufer Teknik Memory Player (first a 16 core, then a 32 core, and having a 64 core built currently).

I think you have to be aware that some DACs could give you that WOW upgrade based on the fact they may have better re-clockers compensating for a budget-ish transport (assuming that is the case in some circumstances).

If you already have a fantastic transport the differences in some DACs is less to do with re-clocking and more focused on the DAC engineering itself.
An example perhaps would be the Audio Note DACs - Audio Notes shun complexity expecting your Transport to be up to scratch - an AN DAC improves significantly with the right transport on the shelf. But if you put an AN DAC on the end of a lesser transport - you are not getting the best out of it.

Another vote for multibit dacs.   Very analog sounding. 

Never.....