If you want true luxury, and spending a bit extra is not a problem, then we recommend the Bellagio.
http://www.bellagio.com/
If you need to watch the budget a bit more, then the Hilton Grand Vacations Club® on the Las Vegas Strip offers good value rooms for about half the price of the Bellagio.
If you are on a very tight budget, then we recommend the Stratosphere hotel. Just about the cheapest rooms you can find in Vegas and it is on the strip.
http://www.stratosphere.com/
If you need somewhere cheaper, then you will probably have to stay off the strip. Which we do not recommend.