Few things others might have already said.
-Great relationship with third parties.
-They don't try to reinvent the wheel. If it's not broke, they don't try to fix it.
-consistency
-If they see something that works, they "borrow" it. If you get a Sony console, you're not missing much.
Sometimes a PlayStation console is the most powerful. Sometimes, it's the least. It's always going to be good enough to define the generation.