Top 5 xbox studios:That's quite an amazing list of studios. There's some others that are very high quality as well: inXile, The Coalition, Turn10, Ninja Theory (maybe 343).
Bethesda
Id Software
Arkane
Playground
Obsidian
All joined Microsoft in the last 3 years.
What would be Sony's top list?
Naughty Dog
Santa Monica
Guerrilla
Insomniac
I would say those are the clear top 4. You'd probably also list Polyphony, Sucker Punch, San Diego, Media Molecule as being very high quality too.
Naughty Dog and Santa Monica are above anything xbox have but after that xbox now have a lot more very good studios.