Aido,
You want to hire a sports car for 5 hours and just drive up and down the Strip. I had a Ferrari 355 spider and it was brilliant. Checkout the website:-here
The V Bar in the Venetian is good for drinks and is full of rich American totty.
The Cheesecake Factory in Caesars Palace does great meals. I had garlic and herb chicken with mashed potatoes. The size of the plate was massive and there were 3 quarters of a chicken on it!!
Hoover Dam is worth a visit.
Where ever you go you can't go wrong. I want to go back, but i reckon it will be another couple of years till i do.