Do Universal Studios on Sunday, and Disneyland the rest of your trip. As Vicki says, discounted SoCal annual passes at Disneyland tend to be blacked out on Saturdays, so all the locals get funneled in to Sunday. I don't imagine that the same situation exists in Universal.
For Disneyland planning, TouringPlans.com has a great Disneyland crowd calendar:
http://touringplans.com/disneyland-r...crowd-calendar