When I was growing up, most fake meat products were pretty grim. Rubbery, spongy, or just plain bland, they were generally avoided at all costs. Today, however, a visit to the health food market or many supermarkets presents a vastly expanded and improved selection of faux sausages, burgers, "chicken" patties, ground "beef," and more. (Chinese and Taiwanese markets often have their own comprehensive range of imitation meats from duck to lobster, many of them colored and shaped to resemble the real thing.) Most of these are made from soy protein.
Yet, I rarely find myself purchasing fake meat products, as I prefer cooking less processed proteins like beans, tofu, and tempeh, along with whole grains and vegetables. I don't avoid meat substitutes completely; sometimes a sandwich calls for "facon," and I love soyrizo in burritos. I used to rely on frozen veggie burgers, which come in all sorts of flavors and can be convenient if you're really busy. (Watch out for ingredients like hydrogenated oils and high fructose corn syrup, though.)
For some people transitioning to vegetarianism, it can be helpful to have familiar meat-like foods to turn to. Others caution against this, as the fake versions don't taste like the real thing and may end up alienating people from a vegetarian diet. In those instances when fake meats do end up tasting and feeling surprisingly authentic, they can be a turn-off to vegetarians. Other vegetarians would be lost without them.
Whether you're a vegetarian or omnivore, what do you think of meat substitutes? Do you use them in your cooking, and how often? Do you have any favorite products or brands?