Personally, mine is joint first between Sandshrew (the cutest), Espurr (most relatable), and Gastrodon.
After those, in no particular order, I like Turtwig (best starter, fight me), the Roggenrola line (little rock guys), the Litwick line (candles and lamps with nefarious intentions), and Metagross (cool robot thing).
Kyogre is the best legendary in my opinion
Scizor! It’s annoying have a trade mon as your favorite. A lot of the games don’t give you a metal coat until late game too. What can you do
Scizor is a really interesting pokemon, and a much needed evolution to Scyther (I think they have similar stats but the better typing with Bug/Steel makes it more viable)
Steelix is also another awesome trade mon, it’s pretty much just a better version of Onix in every way. In later gens it also has a really cool mega!