Best developer in the world (and their best game) and why?

[Leynos]

It's Nintendo. They're not my fave, but their detail and craftsmanship have no rival. My fave is Xenoblade, but if we go in-house, then it's Super Mario World. The best Mario game. While no game is perfect, Super Mario World is as close as it gets.

My fave is 90s SEGA, but no one is more consistently great than Nintendo over the decades.