What is a resort fee? It’s a charge added to your bill on a nightly basis for “services”. These charges are not listed up-front when ordering a vacation package, from a travel agent or on Expedia like sites.
In some rare cases the charge is actual worth the service (provided that you use it). Unfortunately

The following hotels DO NOT charge a resort fee. What you pay at the hotel booking site, your travel agent, expedia or your priceline bid is the final price.

It’s been a while since I’ve updated the info on this site and all I can say is WOW!! Two of the better strip hotels have added hefty additional charges. Additionally the Stratosphere has raised their rate.
Let’s take a look at the Resort Fee Rundown. (for a complete list please use our “Direct Fee [...]

The following off-strip hotels charge a resort fee. Keep in mind that some off-strip hotels, even with an added charge, can be cheaper than staying on-strip, provided that you have access to transportation.
The reasoning for this are lower room rates, lower entertainment costs, lower food costs. All around off-strip resorts offer a better overall value [...]

Guilty! We tricked you… no one downtown charges a resort fee.

The strip is controlled mainly by two companies, MGM Mirage Group and Harrah’s Entertainment. A few independents are mixed in as well (Wynn, Venetian, Treasure Island).
The Mirage group has begun to charge fees at almost all of their properties. On the other hand Harrah’s charges NO fee at all of their hotels.
The following Las Vegas [...]