If you could live your life without hurting another living creature, why would you choose not to?
The fact is, animals are not food, they are not clothes, they are not entertainment - THEY ARE NOT OURS. They are their own entities, and instead of electrocuting them or slitting their throats we should respect that.
OK, so killing animals is bad, you say, but what's wrong with milk or eggs?
The problem with these things is two-fold (and some have different reasons from abstaining than others):
First, the animals you're getting these products from are going to be slaughtered. So by buying these products you are supporting this murderfest.
Second, it's gross! Think about it: humans are the only animals that insist on drinking other animals' milk. And most of us won't even go near human milk! Animal milk is designed as nutrition for their babies, just like our milk is. So why are you drinking it? It's also filled with their hormones, pus and other yummy stuff in addition to weird hormones added by farmers. For more on this see
http://www.milksucks.com/
Eating eggs is gross because they are unborn chickens. I know I wouldn't eat an aborted human fetus, and I wouldn't eat anyone else's either. Free-range chickens are still often killed, and it's also been exposed many times that "free-range" can often mean just a few feet of space. These are not happy chickens.
Veganism is the way to go if you're looking to live a peaceful, healthy life. Bonuses: You'll never have to worry about your weight again; you'll save money (plants are much cheaper than animals at the grocery store); you'll live longer - it's proven.