The Creationist view of the Industrial Revolution moth evolution example takes two forms:
The data was not nearly so unequivocal as it had been made to seem. The moth population did change toward the darker coloration, but this trend varied greatly across regions of industrial England. From the Creationist perspective this raises suspicion of misrepresentation, while from a scientific perspective it says the story is more complex, perhaps involving complex interactions between environment, varying predator populations, etc.
This type of evolution is accepted by Creationists. The observed changes, regardless of how widespread or uniform, drew upon variation already present in the moth population's gene pool. Creationists accept evolution within a species.
Given the second point, the first point's primary importance is as an example of evolutionist dishonesty by taking an inconclusive example and presenting it as unequivocal evidence of evolution in action. There are so many examples of intra-species evolution (dogs, cats, cattle, horses, etc) that no Creationist objects to the possibility, but the moth example has a certain cachet because though caused by man, just like dogs and cats, it was completely unintentional, and it took place in wild, uncontrolled conditions.
If we evolutionists have been carried away by our own enthusiasm then we should fess up to it. On the other hand, just because the actual evidence is not anywhere so simple and straightforward as that presented in grade-school textbooks (some Creationists blame scientists for grade-school textbooks, but that's another debate) does not mean the evidence is inconclusive.
If someone could take a careful look at the evidence (such as it is on the Internet) then perhaps we could get to the bottom of this.
I'm not sure, but you may possibly be asking the wrong question. Evolution proceeds by minute changes from one generation to the next. Offspring differ from parents in only the most superficial of ways. There is no point in time where a catfish, frog or termite lays eggs from which hatch enormously different creatures like seagulls, sloths or turtles. If you're skeptical of evolution because you believe it asserts that transformations of this magnitude can happen in a single generation, then rest assured that it asserts no such thing. In fact, the theory of evolution pretty much rules out anything like that ever happening.
Since evolutionary change proceeds in tiny steps, it follows that a new species differs little from the old. Red squirrels, gray squirrels, flying squirrels, they're all different species, and they all evolved from a common ancestor that differed from them in only small ways, as they differ from each other in only small ways.
So when you ask us to "describe one of the millions of examples of one species evolving into a completely different species," we can't describe anything as spectacular as a catfish evolving into a seagull because the differences between closely related species will always be small. We can only provide evidence of things that have actually happened. Gradual change is what happens, so that's all we can provide evdience for. Closely related species will always differ in only small ways.
I guess the most important point I should make is that I'm sure we're all just as firmly convinced as you are that we'll never find evidence of anything like catfish becoming seagulls.