Out of all the different slot machines available in the world today, one can definitely make the argument that slot machines in the United States are still the best. The modern slot machine got its start in the United States and while subsequent slot machines may have been invented elsewhere, everything from the free slots of the online world right down to the individual slot machines of the offline world have all been proven or discredited upon the ground of the United States. It is there that the destinies of most slot machines are made.
The slot machines in the United States actually tend to be the worst of the developed world from the point of view of odds. Slot machines in places like Las Vegas tend to have the lowest odds of any of the slot machines in the developed areas of the world and what that means in basic terms is that the house edge is higher with slot machines in Las Vegas and elsewhere across the country than they would be in places like Europe or even in some cases Canada as well. For this reason, Las Vegas casinos are able to make more money from their slot machines than their counterparts elsewhere in the world.
There are no online casino companies that are headquartered in the United States and for this reason there are no free slots that are in the United States primarily. When you play free slots at an online casino, you are not playing them from the United States but rather from places most likely in South America and Asia. For this reason, slot machines in the United States are a little less advanced than their counterparts elsewhere around the world, with casinos in the country mostly sticking with the tried, tested and true slots of years gone by.