Apart from cute oriental ladies, (you all know this already), what really sends me is giving it up for a lady that is obviously much weaker than I. I love to be 'persuaded' gently. "For me... Please?" (Melt!)
Being in a position of no choice has it's moments, but I still love the consensual from 'safe, sane and consensual' play.
(Sorry, Tom. Another Club gig.)