Nintendo is my favorite. Always has been, always will be.
The next three are Square Enix, Sega, and Namco, usually in that order, though it varies. I liked Sega and Namco better than SE last gen, but SE is back on top of that tier this gen on the strength of FFXV and Type-O. Sega is awesome for Valkyria, Yakuza, and now Shin Megami Tensei, but I also wish they'd do Virtua Fighter 6. Namco is more consistent with stuff like Tales and Tekken, and I also still enjoy their arcade classics.
As far as individual studios go, aside from the main studios of the above, I like Falcom, Atlus (which I guess is under Sega's umbrella now), Level-5, and Platinum.







