These are my top ten in no particular order, just the ones that quickly come to mind and really left an impression on me~
1. Pawmi - it's really adorable and I would keep it in its basic stage. Pawmo and Pawmot just don't do it for me, because first impressions when evolving into Pawmo I was like "It just learned to stand upright" and it also loses that vivid orange color of its fur, though it gains it back as Pawmot. Speaking of Pawmot, it's essentially just a scruffy adult Pawmo. But, when you think about it, their evolutionary line is as close to an actual real world evolution as you can get in terms of animal physiology. My absolute favorite Pika-clone is Dedenne but Pawmi comes in second place. Morpeko is my least favorite, easily.
2. Frigibax - the first time I saw it waddling around the snowy mountains I literally squealed in delight
love its design, it's like a hybrid frog/fish/dinosaur. Its second and final stages are also really fantastic, too. Baxcalibur always tricks my brain into thinking it's dual Steel/Dragon with a name like that, though, but overall a great design and signature ability, too.
3. Scovillian - the very first Grass/Fire type we get and I think it's really cool, that design is just so good. Very reptilian-looking and I'm all for it. Arven's Scovillian in our final battle was a real threat, too, with such a varied move pool and coverage. That thing hits hard lol also Capsakid is super cute and evil-looking, like an alien. I really like it.
4. Koraidon - quite literally the main reason I chose Scarlet version. Its design is one of the best I've ever seen and spoke volumes to me as a person really passionate about reptiles. Overall its design pops much more than Miraidon, and that's a straight up fact. I also like its animations more, its Apex Build, and how it very much reminds me of Toothless from How To Train Your Dragon
5. Slither Wing - man, that thing is sick-looking. Just when I thought Volcarona couldn't look any more of a monstrous moth. My favorite Paradox mon, easily. I actually would love a plush toy of it, looks so fluffy!
6. Great Tusk - my second favorite Paradox mon. Doesn't get more prehistoric than that, overall great design!
7. Chi-Yu - just a small lava fishy looking so oriental: it really put the hurt on my team with its Lava Plume attack!
8. Cetitan - loved it from the moment it was officially revealed. And it has a killer shiny coloration, too, one of the best among Gen 9 shinies. Also Cetoddle gives me major Gen 2 vibes for some reason lol it's gotta be the eyes and that round body, simple yet effective design.
9. Fuecoco - that derpy look on his face just makes me so happy, what can I say?
I really think it's cool that how, as a Skeledirge, in one of its animations the little fire bird picks at its teeth, just like how real world birds form a symbiotic relationship with some crocodilians in that the bird is safe from predators and in exchange the crocodilian is kept clean. You see this kind of behavior with other birds/mammals/reptiles in the animal kingdom, which is fascinating to see.
10. Toedscool - just for the freaky way it runs
immediately reminded me of the Ramblin' Evil Mushroom enemy from Earthbound the very first time I ever saw it.