Generally your best choices are a good solid Rival Program like:
Absolute Slots, ThisisVegas or Slotocash
or a respectd RTG Group like
CPlanet/Rushmore Group
Club World Casino
Lucky 18
Or Vegas Technology
Casino Coins
Best Casino Partner
In our forum areas you can investigate the programs that display a US flag as a starting point. These tend to be the best US facing Properties available and getting feedback on them is easy.