I have no idea what MY dream proposal would be, but I can share how my dad proposed to my mom (they just celebrated their 21st anniversary on September 21st):
They went to go see a movie together, and after it was over, my dad got down on one knee, pulled out a handbell and starting ringing it, and said "This is your wedding ring." After that, they went to a local jeweler to pick the real ring out. It's a gold cladaugh with an emerald in the middle (I don't know what the specific cut it) because that is my mom's (and incidentally, my dad's, whose birthday is one week after hers) birthstone. They had been dating for slightly less than a year. My mom was playing hard to get "in her head." Sure, Mom. Because that's how "playing hard to get" works
He kept offering dates she didn't want to turn down. And it all happened because his car broke down and neither of them are smokers (my dad's boss's wife set them up on a blind date...third one for him. Just goes to show you the third time's the charm, right?