I used to use lasvagasdirect.com and tripres.com for pretty cheap rates. Better than the casinos own web site. The lasvegasdirect site will tell you which casinos charge a "resort" fee that suddenly makes their cheap rate not so cheap. Generally if you are willing to go to old las vegas up by fremont st you will get the best deals. Sometimes Terribles by the airport has a cheap rate and of course has an airport shuttle. Otherwise you kinda go between the El Cortez and Las Vegas Club.