I dont think ive ever felt bad for an animal when eating it, but killing it is another story.  The first deer I shot and killed for meat was my last.  It may sound kind of hypocritical, but I really have no qualms with eating meat.  I would just rather not actively participate in taking the animal's life if I have other choices available.  Most hunters I know thirst for the kill, but for me it was just kind of a letdown watching the animal I shot cling to every last bit of life.  Fishing doesnt bother me though.