First off...I feel that there are really four candy holidays, beginning with Halloween. Halloween starts it off, then you get into all of the candies to fill Christmas stockings, then there's everything out for Valentine's Day, and you conclude with Easter and all of the goodies the bunny is supposed to bring.
While I think Christmas and Easter bring the best of the candies to the retail market (Cadbury eggs vs. Hershey's candy cane kisses), when it comes to the secular festivities associated with all of these, it's Halloween for me. Especially since Cadbury has started releasing Halloween versions of their traditional Easter candies.
Halloween for freaking sure. I can't go door to door anymore for candy, but I can still get dressed up every Halloween and go to a party where there is candy and much fun happening. Plus just seeing all those little kids dressed in those cute costumes is to die for. If you are lucky enough to be at WDW during the Halloween season the Mickey's Not So Scary Party is also great and the parade is so freaking the best.
I do love both and both have totally different meaning to me. Growing up with a mom who is majorly Catholic Easter and the religious part of it was always very important. She also however made sure on Easter morning that I got an Easter Basket full of goodies. I also enjoyed getting dressed up in a nice little dress and hat on Easter Day.
Halloween is just plain fun. As a kid putting on my costume and going trick or treating was the highlight of the day. My favorite candy was the Snickers bar and still is today. As an older kid I still enjoy handing out the candy and eating the Snickers bars that we bought to hand out.