Call of duty or halo?

I love HALO!  It was the first game where I truly enjoyed FPS.  I always preferred the campaign to vs.

Who says an old lady can't blast aliens?!!!

Neither,  -

Unreal Tournament Sniper Mod,

or Jedi Outcast II -

KFC.. Is that an option!!!

I prefer Halo. Call of Duty gets a little monotonous sometimes.