I went to a wedding at The Four Seasons; it was beautiful. You really wouldn't know you were in Vegas. Most guests stayed at The Mandalay Bay next door - this was great for kids as the pool area is brilliant.
I got married in Vegas - at The Chapel of the Flowers, so not what you want, but it didn't feel tacky and there was no sign of Elvis. We had a short ceremony, and it was very sweet and intimate.
We stayed at the Venetian and saw weddings there and at the Bellagio. The only difference I could see was that those had more people with them (we saw groups of about 20) and obviously the price.
Whatever your venue you will have to go to the Clark County Court to get the licence, and you will see some sights there. When we queued there were a lot of people in fancy dress. The thing is, your ceremony will be exactly how you want it, some people go for tack, others don't. There are a huge number of chapels, and they are all different.
To be honest I found the whole Vegas experience tacky, high end hotels included.
I felt sorry for the dozens of brides wandering around in their lovely dresses amongst the trainer wearing crowds. It is just my opinion though and we saw lots and lots of bridal parties on the hotels so it obviously someones cup of tea.