>>416
It kind of depends on what you mean by "better." Part 1 is undeniably more consistent throughout its entire runtime in terms of overall quality, and Part 2 is a lot more inconsistent; some absolute stinkers can be followed by the best episodes in the show. What Part 2 has going for it is that its good episodes are extremely good.
But it also depends on whether you mean "better" in terms of writing or in terms of quality of animation or direction. As far as well-written goes, there are good episodes all throughout the show. In terms of animation, it's a little harder to explain.
The episodes directed by Miyazaki himself are the most acclaimed episodes of the show from an animation perspective, but they're not the only well-animated episodes in the show and far from the only ones with notable animation. The studio that animated the Miyazaki episodes (Telecom) worked on the movie Castle of Cagliostro and animated 11 episodes of Part 2. For pre-Cagliostro episodes, there are 72, 77, 82, 84, 99, and 105, and for post-Cagliostro episodes, there are 143, 145, 151, 153, and 155.
Besides Episodes 145 and 155, Miyazaki did not have any involvement in the episodes, but Yasuo Otsuka did, who was a legendary animator and a great influence on Miyazaki, not to mention working on the series since Part 1. I find it sad that most people attribute the higher animation quality of those episodes to Miyazaki, because I feel like the Telecom episodes are much more of an accomplishment for Otsuka. He had to work with a bunch of newbie animators who were horrid at their jobs; their work on Episode 72 was apparently so laughably terrible that he had to fire a good chunk of the studio, then animate nearly the entirety of the episode by himself. The rest of the early telecom episodes were about the team trying to find its footing; the best animated out of all of them, I'd say, is probably Episode 99, which happens to be the very first anime to ever be aired in stereo.
After Castle of Cagliostro, the studio's episodes had a significant increase in quality; 143 and after are all really well animated and fun episodes. 143 is one of my personal favorites due to it being storyboarded by Yuzo Aoki, a great animator who has a really unique style (he was the lead animation director on Mystery of Mamo). It's cool to see his storyboards, which normally get adapted in his own style of limited animation to Telecom's high quality standard, leading to one of the most visually detailed and charming episodes of the show from a visual perspective.
But I could go on forever about the show. Part 2: What it lacks in consistency makes up for it in artistic variety. I didn't even talk that much about Yuzo Aoki and his fantastic work on the show or the Oh Pro episodes.
I feel like it also kind of boils down to there being no real proper categorization in official home releases (because it's not standard), and the home video releases were either random episodes or the full chronological set. I feel like it'd be way more useful had they categorized episodes by who worked on them rather than their numbers. A good resource for knowing who worked on what is on this page is:
https://web.archive.org/web/20201111180048/http://www.pelleas.net/aniTOP/index.php/lupin-iii-part-2-creditsThis guy did a great job.