I agree that it propably depends from the particular cats/dogs temperaments, but I would suggest Scottish Folds. My foldie kitten is just so sweet, and 'ragdollish' (I don't personally know any ragdolls so I can't really compare), you can do anything to him an he just purrrrrrrs. Like everytime I clip his claws, he just lays there and usually falls asleep or just stays on my lap wanting me to rub his belly.
And you can handle him very easily, paws, ears, teeth, whatever and he doesn't mind.
All his siblings are the same.
And dog breeds, I would say Labrador. All the Labradors I've met are just so sweet, laid back and seem like wise dogs (when they're a bit older..
). They also obey very well.