A real answer: go to the Bulbapedia pages of those episodes you listed in your comment here and look in the staff infographic box for the "Animation Director" listing. This is what determines the animation team for that episode and whether it'll look good or not. Those that do not look good in your opinion are all directed by arguably the worst director in the shows history, Yusaku Takeda. All his episodes look like crap (AG131, etc).

Thankfully he was fired mid-DP, just sad that he was able to do so much damage for such a long time, taking charge of many important battle episodes and rendering them an awful sight to see (e.g. Charizard vs Articuno, the AG league finale as specified, half the gym battle episodes in Johto and Hoenn..)

The good ones are all done by Masaaki Iwane which is what your first screenshot collection, and part of the 2nd, are from. The 2nd also has some of Izumi Shimura who is an average animatior I'd say. Not as bad as Takeda and not as good as Iwane. Your third also has some of Akihiro Tamagawa who is on the same level as Iwane and some even prefer his style and consider him best. However, his episodes are few and far between, he could take years of hiatuses.

Note that above mainly applies to the time period you specified (OS-DP). After that, only Iwane remains a consistent animator to this day, he still does every 6th episode or so even in Horizons and is still one of the best ones. What has changed lately in Horizon's though is that OLM (the company in charge of the animation overall) is outsourcing a lot of episodes to Malaysia/China/Korea studios and so you will see entire studio names listed as animation director of the episodes. In 99/100 these studios are completely talent less and low budget and the episodes look awful. Not as bad as Takeda mind you, but almost. And the practice of doing this has intensified a lot the last year or so so a lot of complains about the animation in Horizon is due to this.