OK, this thread was started by my invitation, and I agreed to state my case on the matter, so please bear with me on this long post, because it takes a lot of groundwork to establish the argument properly.
First of all, I'm going to treat "good or bad" from a moral perspective exlclusively.
My thesis is that eating meat is immoral except in the rare case that you can obtain it from a wild animal that has died of accidental or natural cause.
Premises:
1. Morality is based on our potential to cause existential harm to other concious beings. For example, we don't consider it immoral to toss a rock into a pond because neither the rock nor the pond have the capacity to suffer either physically nor emotionally. Tossing a baby into a pond is clearly immoral, as the baby would suffer.
2. Moral deliberations consist of emotional components including disgust, contempt and anger, but reason should override such rudimentary justifications using a systematic set of principles and values.
3. Sometimes moral values come into conflict, and in such cases, we must either turn to deontology or utilitinariism to decide which of the two values in conflict overrides the other.
4. Harm is inflicted when you inhibit a sentient being's capability to flourish (flourish meaning to forge a satisfying life). Examples of inhibiting a creature's capacity to flourish would be to inflict significant physical pain, to inhibit it's necessary physical territory, to inhibit it from participating in their natural social environments (if it applies to the given species in question), to inhibit a humans from participating in culture and recreation (it's not that likely that other creatures need those things, but humans need them) and there are many other examples.
5. All concious beings have the capacity to suffer at least physically, and many of them emotionally.
6. To act in a morally impermissible way is to unnecessarily inflict harm on a being.
7. Killing an animal abruptly inhibits its capability to forge a satisfying life, as well as often induces physical and emotional pain during the killing process.
8. Humans are omnivores, therefore humans are able to choose a vetarian diet. Since plants don't have the necessary neural structures to feel pain much less experience emotion, eating plants is morally permissible.
9. Since humans can choose non-sentient beings for their diet, it is immoral to choose otherwise.
Just to be pre-emptive, a common argument is that it is natural to eat meat. This may be so, but this does not make it morally permissible. It is also natural to fight, but it's still immoral to do so (except of course in certain exceptional cases). Also, the fact that other creatures eat meat is also not an argument in favour of humans doing so, since some other animals don't have a healthy alternative to meat eating, nor do they posess the mental capacities necessary for understanding the effects of their actions on their prey. We do however understand, so we are responsible for our actions.
Sorry for the long post, but it was necessary to substantiate my claim.