I had temporary bridal insanity and made the tactical error of purchasing a dress that was essentially backless.
I figured there had to be a bra option out that that would work,  I mean they've almost nailed an invisibility cloak for crying in a bucket!

I ended up with three:
#1 NuBra: Chicken cutlet looking things that stick to your boob.. not good if you have boobs already. They basically just hung there and further weighted them down. Exactly the opposite effect I was looking for.
#2 Very Bare bra: Formed foam number with under-wires with adhesive backing. This one seemed promising as it did support and offer smoothness and nipple coverage but the adhesive wasn't strong enough and it kept popping off.
#3: This Maidenform contraption.

I chose Maidenform out of sheer desperation. As long as I didn't gesticulate too wildly, it mostly stayed in place but that was ONLY because the dress was holding it down in front.  I intended to use double sided tape (which disappeared along with the flower girls shoes so I just went without).  In the end, it was the only bra that even remotely worked for me. I did have to go in the bathroom and regroup a couple times and I did fuss with it a lot in general but at least I had SOMETHING covering my business in that impossible wedding dress!  PS. I have a large-ish bust, that may have helped anchor the thing a bit too...
PSS.. Ultimately, I didn't love my wedding dress enough to go through all that. I honestly wish I would have gotten a different dress.  I hope this helps some other desperate soul..