Digital Interconnects - Which one is the BEST ??!!

I have not put forth much effort to really test it, but I have never heard any difference in my system when it comes to audible changes from things in my system transferring the digital signal.  I've heard differences from tubes, power cords, interconnects for reference.  It's been a while since I did anything with optical/toslink in my system and currently use SPDIF.  I recently upgraded from a cable from Blue Jeans Cable to a Cinnamon from Audioquest and didn't hear any difference.  

Toslink does have limited bandwidth so cannot transfer high resolution files.  I tried a Schiit DAC and had to use SPDIF to get the files to transfer.  I don't normally use high resolution files, so this was a bit of a surprise to me.

I'm not saying that digital connections cannot make a difference.  I've just not heard it in my system and if I'm honest I'm happy to avoid that rabbit hole.

1. Ethernet.

2. USB.

Add an audiophile switch e.g. Bonn 8 or English (something) with a LPS.

Ethernet could only be considered if one has dac with internal steamer. Ive seen reviews where external streamer with usb beat ethernet in on streaming dac. This would be case where external streamer superior to internal streamer and dac has very nice usb board.

I believe  OP is asking about cables for digital physical media, with streaming  in play preferences will be much more variable.

Yes, original question in my case is mostly for CD Transport to DAC, CD player to Amp.

+1 Baylinor. Between CD transport and DAC - depends on which is available. I would use I2S over AES, AES over Coax, and avoid optical if possible. 

Between analog output from CD player to DAC choices are RCA or XLR. 'Best' depends on wether both devices are truly balanced or not.