I'm partial to the ET ride if you hate crowds universal is the way to go because there are literally roads between all the buildings, lots of space to walk around. harry potter world connects the parks in the back using the train which is awesome, no more going back up front only with park hopper, avoid all restaurants in the park and simply hit city walk to eat way more choices and more food for the same price or cheaper, I'm 6'4" 290(not fat) I can fit on almost all the rides there, any Disney park I go to I'm fucked due to legroom. make sure you due hagrids rollercoaster, its so awesome, it bridges adrenaline ride and show ride together!
if you have to choose between the two id do universal it has more kid friendly stuff.
universal has a simpsons area where you can get the donuts and duff beer, im pretty sure its just miller light tho, and they got turkey leg stations now i heard!