Universal Studios, no question (caveat: we've never been there, but I've read enough about it to be familiar with its attractions). Hollywood Studios isn't even a full-day park for us, even though we only visit once every 18-24 months. The "rides" (by which I mean, "attractions that move me physically from one place to another in some fashion") can be completed in the first two hours after park opening. After that, it's a question of, "which show or two that we've seen multiple times before would we care to see again?"
I'm sure one could easily spend a full day there, savoring the "details," but I have to admit -- I haven't the patience (and my two small children certainly don't) for too much sitting on bleachers and meandering around. I want rides! RIDES!!!
Universal Studios has more of them...
Now, if you asked me the same question and the comparator was Magic Kingdom or Epcot, I'd take either of those two Disney parks over any other park, any day...