I really like Saguaro Scramblers Agility Club! They are dual sanctioned, so they offer both USDAA and AKC dog agility trials. They are a small club, so you can expect to need to volunteer to keep the day moving if you enter one of their trials, but that is not a bad thing. They are super friendly, encouraging, and hard working. Their trial site locations vary, so be sure to check the premium address, because you will not be driving to the same park for every show. They use Launch the Dog agility equipment, so it is very safe. However, the independent jump cup design of the Launch the Dog equipment can be a pain.
Overall, they are a great club, and I would highly recommend attending their trails (in both USDAA and AKC).