In my opinion, Blizzard and Bungie's game development styles are very similar.
Blizzard tends to revolutionize gaming, but also sticks to a "if it ain't broke, don't fix it" development habit. Bungie does the same.
But both add new features into the game that spices up the game, and turns it into something revolutionary.
But I'd say that Blizzard's games are more longer-lasting and more fun than Bungie's.
People are still playing 10 year old Starcraft, and 5 year old Warcraft 3, and still obsessed about WoW (even though I hate WoW)
Bungie has also created grand games, but they are FPS's, and FPS's usually live for a few years, than die.
Like Halo 2, which was replaced by Halo 3 (which is a much better game)
They are both my favorite game developers, other than DICE and Infinity Ward.