I've been to two weddings in Vegas, and both were very nice! One was off the strip near the Boulder Station casino called Victoria's. It was a nice ceremony in a room that was nicely painted with clouds and columns. The reception was gorgeous. The food was good. And our outside party was so hopping that people at other receptions asked if they could come play with us!
The other wedding I went to was held at the Flamingo. It was outside, near one of the pools. It was a small wedding-about 30 to 40 guests, and was very very nice. They had the reception at a nearby restaurant called Roy's and it was truly exquisite! Amazing food.
There are so many options for your wedding in Vegas. You two really should take a trip up there and check out all of the different venues and packages available.