Which level 1 monster do you like the most in Heroes of Might and Magic V?

You weren't comparing them quite right; it would be better not to compare them 100 to 100, but rather compare the increase in numbers against the increase in numbers, or for a certain amount, how many of one you could buy versus how many of the other, and then compare them. Otherwise, each unit has a different price, and each wins in its own way.