Depends on how you value consistency and how much emphasis you put on Curry's downfall. No matter how you split it, Curry's résumé takes a massive steaming shit on Lopez's. Lopez was a better technician IMO. He also had a much more aesthetically pleasing style.
This is tough. What I would say is: 1. Curry's resume is without question deeper. 2. 84-85 Curry was arguably the better/more talented of the two. 3. However, it's hard to envision Lopez losing P4P to a Honeyghan-level fighter. Lopez would probably annihilate a guy like Honeyghan. 4. Despite being less physically talented, Lopez was more complete and without question had a much better chin. 5. I'm pretty critical of Lopez, but really, his resume was a bit better than given credit for. Curry still has bigger wins, especially Starling. So, it's really a tough call. Greatness might be a wash. Lopez has become more glorified, however, at no point was Ricardo Lopez the P4P #1. Curry was. In terms of better? I'd probably go with Lopez. Again, Finito was less of a physical phenom, but more skilled and tougher. Lopez was also a bigger puncher, P4P, FWIW.
It's a matter of how you view a short prime with some good names on the resume, and also being considered as the best fighter for a spell VS being undefeated, consistent, many title defenses, but with a less stellar resume. Hard to say honestly. I would say that Finito was greater just due to the fact that he kept everything together in the long run, had the intangibles, remained unbeaten, and didn’t fold even when met with adversity (Rosendo Alvarez). But it would have helped if he had his share of facing other talented fighters within his weight class. Curry at least fought a defensive genius in Starling and a fast, slick Ali-type like LaRocca. Curry had hit a much higher plateau than Lopez, although Lopez remained great much longer. Skill wise I think they’re both really close as well. Curry showed much better infighting while Lopez had much better footwork. At their best they both looked close to flawless in terms of technique. Just beautiful style to watch. 2 fighters I greatly admire and also consider them the ideal textbook boxer-punchers.