If zombies are in a game, the chances of that game being good are better than the majority of games out there.  This is because zombies are the coolest thing in the world.  Even cooler than ninjas.  Zombies eat brains.  They can be fast or slow.  They are hard to kill unless you are a good aim or have a good melee weapon.  They are just, in general, fucking amazing.

In turn, any zombie presence in a game exponentially increases the awesomeness of a game.  Even if we look at something like Resident Evil Survivor, which wasn't the greatest game out there...it was still a better game than the majority of crap that exists.  Land of the Dead: Fiddler's Green was another example of this.

Therefore, I believe that more games should have zombies, even if it's only one or two, because it would improve the quality of games in general.

The end.

Questions?  Opinions?