Vegetarianism? Pros and Cons

[Speedlimits]

I'd first like to say that I currently eat meat,fish, everything that I like. I am interested in hearing people's views on going vegetarian and what kind of food vegans/vegetarians eat in place of meat/fish. Also the reason I have not gone vegetarian/vegan is because I feel like it would not make a difference and that the animals that are being slaughtered would be killed anyways.

Is this flawed thinking?