Throughout Cataclysm I spent a lot of time explaining to hunters that the pet paradigm had changed and there was no longer one right answer to "What is the best pet?" Instead of being able to answer cat, or wolf, or whatever the pet of the moment was, the answer was: it depends.
Well, with the changes to hunter pets in Mists of Pandaria the answer is now that it depends even more.
The best pet to bring to your raid or heroic is going to change based on your group composition -- and in fact can even change based on the skill of your team members. Let's first take a look at which pets bring which raid buffs, then get down to how to select your pet.
But fair warning in advance: choosing the right pet isn't a matter of following a flowchart or plugging in an addon. You have to use your brain (in your head).