Given the same quality of devices:
I2S (HDMI connector):
I2S is best because it usually connects directly to the D/A, bypassing any substandard internal reclocking in most DACs. This means that you can drive it with really low jitter devices like this and get superb results:
https://www.audiocircle.com/index.php?topic=156409.0
A high-quality I2S cable is necessary. Usually at least $800
The downside is that it is difficult to do galvanic isolation for I2S, although there is one add-on HAT board for the Raspberry Pi that does this.
AES/EBU:
AES/EBU has the potential to be second best but the problem is finding a really good low-loss cable with matched impedance throughout, including the connectors. The connectors and wiring inside the DAC are usually not 110 ohms either. The positive is that it has some level of differential common-mode noise rejection. If there is an internal reclocker in the DAC on this input, this will probably limit the performance you can get.
S/PDIF coax:
S/PDIF coax can be outstanding provided that you use a good BNC-BNC cable (RCA adapters as needed) and use a DAC that does NOT have a substandard reclocker internally on the coax input. Such DACs are the Metrum line, Audio Note and others. With these DACs, one can add an external reclocker in the coax cable like the Sychro-Mesh to achieve truly low jitter and therefore excellent imaging, dynamics and liveness:
https://www.audiocircle.com/index.php?topic=157348.0
USB:
USB is the most problematic of the bunch. You must jump through a lot of hoops to get really stellar performance. It is possible though, using the right playback software. A critical piece is the USB cable (I like the Wireworld Platinum) and an external USB cable regenerator like this:
https://sotm-usa.com/collections/sotm-ultra/products/copy-of-tx-usbultra-regenerator-1
Two USB cables are needed with this device.
A well-designed low-jitter XMOS USB interface is critical and galvanic isolation is desirable. Most built-in USB interfaces in DACs are not great IME.
Toslink:
Forget it. Not good enough.
One that you did not mention is actually the best of all of these:
Ethernet:
You can get external Ethernet renderers or Ethernet built-into a DAC. Some support Roon and others support DLNA/UPnP. IME DLNA SQ is better. The computer playback system does not matter, but the playback software does. I personally use freeware; Linn Kinsky/Minimserver/BubbleUPnP. Runs on Linux, Mac and PC. The one requirement is that the router or switch be AQVOX type or similar and that the Ethernet cable from the switch to the Ethernet interface be high quality. I use Wireworld Platinum myself with superb results. Ethernet beats everything else I have heard at shows and in my own products. Here is an external renderer, the Interchange that achieves 10psec of jitter at the end of a 4-foot coax:
https://www.audiocircle.com/index.php?topic=156409.0
You can stream or play local files with Ethernet renderers. Some are built-into the DAC, like my Overdrive SX.
Steve N.
Empirical Audio