My wife and I are *mostly* vegetarians, mainly due to the poor treatment of many farm animals, the harmful effects of ranching on a massive scale, and also for health reasons.
We do however still 'cheat' by having yogurt, milk and cheese regularly, fish (once a week), and meat even more occasionally (once or twice a month).
From a dietary perspective there are certain vitamins found in sufficient quantity only in animal products, but dairy can give you 100% of what you need, so we try (probably not very well) to include ethically produced dairy in our diets. Animal flesh isn't necessary.
We never have meat at home, but we do eat out occasionally. From the perspective of a Buddhist or someone who believes you shouldn't eat meat, plenty of sentient beings are killed during the process of harvesting grains or vegetables, so eating meat isn't much worse of a crime, though it is obviously preferable to avoid.
Also, vegetables are tasty. Tonight we're making some chaat and a few salads