I grew up in California and my parents love Disneyland. By default we went to Disneyland every year for our family vacation, which I loved. Since I grew up going to Disneyland as a kid I love going there as an adult as well.
Although, I also am not a huge fan of crowds; I will do a lot to avoid a huge crowd of people, so a trip to Disneyland needs to be well planned. My favorite time to go is September because it is still sunny and warm but the crowds from the Summer have dissipated (with the exception of Labor Day weekend of course).
Although, not everyone tries to avoid crowds like I do, because by avoiding the crowds I also don’t get to see as many shows and occasionally a ride is closed for maintenance. This is because when their aren’t as many people in the park Disneyland will take time to do maintenance on rides and not show as many performances each day of each of their shows like Fantasmic!
Depending on what your family is looking forward to enjoying while at Disneyland will depend what time of year you should go, which is what the below chart can hopefully help you decide.