I call it a pacifier or a paci. I noticed most people I know seem to call it a binky. I do know one person who calls it a plug and for some reason that drives me insane.
We use the terms pacifier, paci, binky, and bink-bink interchangeably here. I don't think I've ever heard it called a dummy before but I can think of certain people that I have called a dummy.
ETA: Dh has been known to call it the "baby shutter-upper" on occasion as well.
I chose other. We always called it a paci. Sort of surprised that wasn't a choice by itself since it's a very logical shortening of the proper term pacifier.