Ok, you want an idiots guide? Let me give you the logic behind meat. A rule of thumb, if you will.
The quality and taste of the meat of any particular animal is most often related to where the cut of meat comes from. Once you understand where the cut of meat comes from, you then understand the quality of meat. In general, the more the muscle is used, the tougher the meat.
For example, chicken legs versus chicken breasts. Chickens are kept in cages so they can't use their wings and exercise the breasts. The result is tender breast meat. However, chickens must stand, so in comparison the leg meat is tougher.
Veal is from baby cows kept in very small pens. They are kept in pens so that the muscles never get used, so virtually all the meat is very tender.
Otherwise, on pigs or cows, the two strips of back muscle are the most tender. In fact, those are the "tenderloins". I mean, when was the last time you saw a cow dead-lifting anything? Come on, those have to be some tender muscles.
Fish? Well, fish is fish. Some sushi freaks will insist there is a difference, but there isn't really much difference aside from the belly meat vs. everything else.