Tough question for me, I can't decide
Cats = Super cute but assholes
Dogs = Loyal and more interactions but not as cute as cats (huge minus that they can't age long so it hurts a lot to lose a companion, cats also heartbreaking but not as tough imo)
I would give both A-Tier
S-Tier for me are definetly Parrots, they are smart, life-long companions (they can get over 50 years easy!) and if you teach them well they can literally speak with you, you can go with them anywhere and cosplay as pirate 24/7