You can only pick 1…

The Art of seduction is my -#1 because it’s the start of the attraction that makes one want to submit.

The best is when your mistress is working hard beating you with an appropriate flogger while you are uncontrollably aroused, submissive and desperate and also aware that she is completely focused on her own sadistic satisfaction to the point that she is sexually aroused.

When she stands in front of me, looks me in the eye, and softly answers "Yes, I consent and submit."  
That's the key to all the other fun.