Same advice I posted before.
During EE, the ride choices are limited - but they usually open the rides that get the longest waits during normal hours. USO typically opens Gringotts and one other ride (Mummy or Minions are the most common, I think). IOA usually opens Forbidden Journey, Hagrids, Velocicoaster, and Hulk.
Our preference is to go to EE and ride whichever of the HP rides are open. That allows us to get those rides in while the HP areas aren't too crowded, then we can avoid those areas the rest of the day if we want to.
The second priority is any of the non-EP rides - right now, Velocicoaster is the only non-EP ride that doesn't fit rule #1 above.