I vote for Role Reversal as most erotic, with the buttplug day as second. Though as David said, if they didn't have the love and other special aspects of their relationship, I would likely not find any of it erotic.
I've been busy this morning making pumpkin muffins from the gallery. I'm not a very good cook, and I had to fudge a few of the steps here and there, but they turned out pretty yummy!