The third one has the slight edge and that's the one I like best so I'm gonna go with #3! It especially seems to be the popular choice with the guys and I really want to impress my boyfriend since it's actually his friend's wedding =P Thanks for all your answers everybody!
I really like both the first one and the third one :) The good thing is, you can most likely find something similar to the first one at a different store. I would seriously try Sears. I'm not sure where you live, but I know I have seen similar dresses in many stores. Add a broach or pin to the dress in the same place to get the same look . Or pair it with a sequin clutch. Or even get a pretty sparkly hair clip to pin your hair :)
The third one is also very pretty, it's sparkly but not too much.