That all depends on what kind of dress/gown you'll be in.
You don't want to look like so many couples I see lately - the woman all dolled up in heels and her date in ripped jeans and a backwards baseball cap. I know ... that's extreme, but you need balance, so what will you be wearing?
I'd like to be helpful, but I need more information.
P.S. Some of the suggestions below are good, but if you're going to be in something that's all poufy, beaded, sparkly, white, and gorgeous and he's wearing some khakis or jeans or anything casual, you'll regret it forever.
If he goes casual, you really should, too ... or you might consider having his dad or best man work on him.
The white suit and black shirt will make him look like a mobster, tho.
If you really don't want a "suit", then what did you have in mind? And what are you wearing?
