This is completely subjective of course - My preference is ivory. It's softer, compliments more skin tones and was the choice I made for my wedding, so of course I like it better. When it comes down to the day, all those little details won't seem to matter so much, so try not obsess...just go try on dresses regardless of white shade and see what happens. Like they say, when you try the right one on, you really will know.

My vote is for another pastel color, especially for you. Why limit yourself to white or ivory? What is the color theme of your wedding?