Been to Vegas twice and loved it more the second time. Stayed in Ballys, very good on price and in the middle of the strip. Hoover dam is good, and get a helicopter ride to the grand canyon as it will be faster than driving and the views are spectacular.
Do visit old Vegas to, just to say you been there.
Went on a time share thing, wasted about 4 hours in the morning but got free tickets to see Lance Burton(amazing) and $120 to play in any casino which we managed to convert back into cash, happy days.
I drove from the Welcome to Vegas sign to the stratosphere and that was 4 miles long, lots to do.
Have a good time