Was just searching for a hotel in Las Vegas and found that the Hilton was coming up cheaper than many of the 2/3* 'budget' options!
The price if you search Lastminute.com is around £40/night (most sites are giving prices of £50-60, including the official Hilton one).
HOWEVER.... If you first search for 'Las Vegas' on Skyscanner.net (direct link button), you get displayed an even better offer and when you click through to Lastminute from the sky scanner link, the prices of the Hilton hotel are dropped even further!
Price seems to be Monday-Thursday with very good availability (I looked in May). More at weekends, but still well below standard. Lastminute says it's '70%' off...
You can then go onto Quidco and load up a Last minute page to replace the cookie with a quidco one, keep the discount rate and collect 7% cashback!
EDIT: Direct link seems to go to Hilton website now...? Use: http://www.skyscanner.net
to search first before clicking through to Last minute.com to book.