1) The Stratosphere
The Stratosphere Hotel and Casino is located on the north end of the Las Vegas strip. You can't miss it -- it's the hotel with the 1200 foot tall tower that resembles the Space Needle in Seattle. I have stayed and played at the Statosphere many times over the last five years, and I can tell you honestly that I have WON money on the slot machines more often than not. In fact, the only time I've lost money playing slot machines at the Stratosphere casino was the very first time I stayed there, back when I was a slot machine novice and didn't know what I was doing. The slot machines at the Stratosphere casino seem to be much looser and more generous than any of the other casinos on the Las Vegas strip. My theory as to why the Stratosphere has looser slots is that since it is located on the very north end of the strip -- the "ghetto" part of the strip -- the looser slots are to bring in tourists who normally might avoid this part of the strip. (Read more on the Stratosphere Hotel and Casino here)

2) Sam Boyd's Fremont Hotel and Casino
Quite frankly, the casinos located in the Fremont District (also known as "Old Vegas") seem to offer better payout rates on the slot machines than the casinos located on the Las Vegas Strip. The very BEST casino in the Fremont District as far as I'm concerned is Sam Boyd's Fremont Hotel and Casino. I have played slot machines here several times and so far have always won money! The slot machines here seem to have better payout rates that the rest in the Fremont District. Bonus rounds come more often and are more generous, "big win" spins come more often and are more generous... plus the Fremont Casino also has super cheap drink specials at the bar ($1.99 margaritas and $3 domestic beers) which most Las Vegas casino bars do not have. Of course, you do get free drinks when playing the slot machines here. The neon billboard outside of the Fremont Casino advertises "loose slots" and I do believe that to be true.

3) Boulder Strip casinos
The Boulder Strip is located on the Boulder Highway (east of the Las Vegas Strip) and is where the locals go to gamble on the slot machines. The locals go there because the Boulder Strip casinos offer higher payout rates on their slot machines than the casinos on the Las Vegas Strip or the Fremont District. There are about a dozen large casinos the Boulder Strip which include Sam's Town, Boulder Station, the Eldorado, and Jokers Wild, among others. I personally have never made it out to any of the Boulder Strip casinos since it is not convenient to visit if you are a tourist using the bus system, but according to many Las Vegas casino discussion boards these casinos have the best payout rates on slot machines in Las Vegas.

There you have it... the best and the worst Las Vegas casinos to gamble at on the slot machines. If you visit Las Vegas and plan on playing the slot machines, good luck, have fun, and don't forget to take advantage of the free drinks that the casinos give you while playing the slot machine games.