In order of SQ
1. I2s however this is my project for this year to implement I2s so I cannot verify this in practice, only research.
2. USB controversial choice here but with the correct DAC and DDC it is capable of outclassing AES/EBU.
3.AES/EBU Excellent and for most people it will provide the best sound.
4.BNC SPDIF Very, very close to AES/EBU.
5.RCA SPDIF Least favorable of the above.
6.Toslink usually only capable of 24/96 kHz and is the worst choice you can make. Only suitable for a soundbar if you don't have another choice. Better than HDMI eARC however, but that may be down to equipment.