Makes the game look much better than if it doesnt have it, why do you think gears of war is so popular?

no i prefer more cartonny games like the wind waker.

Yeah the green blood in ninty games looks wrong

Depends on how it's used. A game like unreal tournament, where frantically moving from target to target, if it had no gore or exploding bodies, it would almost null the sense of the perfect kill that gets accompanied by a yelling announcer screaming ULTRA KILL, GOD LIKE! etc etc... A game like Mario however >_>; Definitely not needed. If your going for a violent setting or mood, gore and blood can be infinitely useful.

Blood/gore won't make me dislike the game if it's done properly... As everything else, it should be present when it makes sense.

I think it fits the mood of realistic games , but some games get unnecessarily carried away ( Gears) even if they are fun games.

It all depends on the game and the presentation. Some games are more "complete" with the blood and gore (like survival horror games) and some games wouldn't even make sense with blood and gore (like Mario or Sonic).

Hell yeah, the gorier the better,

Depends on the game.  Ratchet and Clank with gore wouldn't feel right, UTIII without gore wouldn't feel right.