Back in the day studios used to specialize. Universal made the best monster movies, MGM did all of those crappy musicals, and Warner Brothers was the king of the gangster picture. Republic churned out the best serials, Columbia gave us Three Stooges shorts, and I don't know what the hell 20th Century Fox was doing before Star Wars. You also had the cheap ass studios like Monogram and PRC that are responsible for all of those public domain videos companies like Goodtimes used to flood the market with back in the 80s.
Warner Brothers also put out the best cartoons. Sure Disney is all over the place with their feature length flicks and theme parks, but who watches Disney shorts anymore? Mickey Mouse had nothing on Bugs Bunny.
These days you don't know who makes what, though it seems Warners is big on superheroes. Of course, if you want to go international with it, Toho is still the place to find movies about giant radioactive lizards.