So Why Do People Say "Game A" is Better than "Game B" Without Even Playing "Game B"?

[TruckOSaurus]

'Cause Game B sucks. Everyone knows that.

Seriously though, while I can't say if a game I haven't played is "objectively" better, I know what I like and dislike. So, for example, in the recent thread pitting Resistance vs Metroid, I can say without a doubt in my mind that I prefer the Metroid series over Resistance even if I've never played a Resistance game in my life.