Hi Angi,
Welcome to the site. I think either location could be great. We had friends that did Vegas a few years ago with great reviews. We almost did Italy, but decided to do the beach.
When I was picking a place I narrowed it down by things like being a short flight for people who may not be able to get a long time off work and cost for guests. I also wanted an all inclusive resort to make things easier once we got there.
I don't think you can go wrong with either location. No matter what you will have a great time and lots of great stories.