Irreducibly complex systems
The straw-man argument for irreducibly complex systems is that irreducibly complex systems are not only expected to happen in nature, but were predicted almost a century ago by Hermann Muller. Two steps to making an irreducibly complex system:
1. add a part
2. make it necessary
When a creationist asserts that the eye is irreducibly complex or that the immune system is, it's really nothing more than picking up the latest creationist buzzword.
"gradual Darwinian evolution can easily produce irreducible complexity: all that's required is that parts that were once just favorable become, because of later changes, essential. " - H. Allen Orr
Chance and complexity
On arguments to do with the vast complexity seen in nature, the straw-man is that evolution is not a chance system. Mutations are random, but natural selection is non-random. Let's take an example of a game of chance that involves selection: Yahtzee. Each turn the player has 5 dice to roll and gets three rolls in order to roll one of many various combinations. To get a Yahtzee, the player must in those three rolls get all 5 dice to the same face value. To roll a Yahtzee on any one roll, it's a 1 in 64 (1 in 1296). Because the number of the first die can be any, it's only the other 4 dice that need to conform to it. So doing three rolls by scratch gives the chance to be 1 in 432. In a game there are 13 rounds so to roll a yahtzee over the course of a game purely by chance is around 1 in 33.
But Yahtzee is not played that way, the player has the ability to select dies from each roll in order to carry on. To roll two dice of the same number, it's a 671 in 1296 chance or ~0.52. This means for the next two rolls there are only three dice to roll. The odds suddenly become of rolling all three dice to that same number over two turns as 1 in 108. One rolls another of the kept number, that means on the last turn there is a 1 in 36 change of getting the Yahtzee. If on that 2nd turn two of the three dice are the same as the kept dice, then there's a 1 in 6 chance on the final dice.
A convoluted example, but it does show how cumulative selection can bring about immensely improbable events in relatively short periods. Selection is not random, life is not a product of chance alone.
There are no transitional forms
The denial of evidence is one thing, but the straw-man argument to do with transitional fossils is the type of forms that are criteria. For instance, the Crocoduck. The chimeras that are posited have not and do not exist in nature, it would be an evolutionary impossibility. Crocodile and a duck would also be a common ancestor to all birds and to all dinosaurs as well. To think that one creature 200 million years ago had all the avian features that hadn't evolved yet is absurd.
There are plenty of transitional fossils in the fossil record, archaeopteryx first discovered in 1861 of a bird that still had many saurian features. Likewise many other dinosaurs have now been discovered to have feathers as well as other intermediate forms like microraptor. The wealth of transitional fossils found is embarrassing for anyone who asserts that there are no transitional forms.
One species turning into another
The straw-man on the proposition that one species such as a cat could give birth to a species such as a dog is that it asserts an impossibility, really it's a similar straw-man attack to the crocoduck chimera attack. A cat can't give birth do a dog, it doesn't have the genetic code to do so. Instead a cat population could split into two and become two different species. Over time these differences will accumulate in the genepool.
Once there is mutation, selection, adaptation, genetic drift, and speciation, there are the mechanisms under which evolution acts. Speciation creates diversity and stops the spread of genes horizontally, and once you have a mechanism that stops gene flow then isolated populations can accumulate different mutations and over time will see very different paths. A cat can share it's genes with other cats, and over time isolated cat populations may no longer be able to breed, but the mutations in a cat will never make a dog.
The laws of thermodynamics
The straw-man of arguing that evolution violates the laws of thermodynamics (and in particular the 2nd law) is that evolution has nothing to do with the physics of heat. Evolution is no more a violation of the 2nd law of thermodynamics than a baby growing from a fertilised egg. To think of the process in basic terms, each time a baby is born there is slight variation from it's parents. This variation is inherited and then passed on to it's children. And so on down the line. How does any of this violate the dynamics of heat in a closed system?
Evolution is a religion
The straw-man of calling evolution is a religion is that just because something is a religion it doesn't mean it can be dismissed without consideration of the evidence. It should be made clear that evolution is not a religion, it's a scientific theory that is supported by evidence. Calling anyone who accepts the theory of evolution Dawrinists, or trying to cast doubt on the validity of the concept by saying Darwin recanted on his deathbed is trying to dismiss it the way a Christian would dismiss Islam. Science does not work that way.
Evolution is only a theory
The straw-man of calling evolution "only a theory" is that it uses the colloquial definition of the word theory when the scientific meaning of the word is vastly different. Evolution is a scientific theory, but what that implies is vastly different. While the informal use roughly means conjecture, in science it means a rigorously tested hypothesis that is supported by the evidence. Gravity is a theory, germ theory is a theory, a theory explains the facts.
The straw-man around saying evolution is wrong because it promotes immorality is that the behavioural consequences of teaching an idea has nothing to do with the truth of the idea. Even if (and it's a big if for a completely unsubstantiated claim) teaching evolution led to greater crime, the idea still has the same scientific merit. Same goes for eugenics, what people do in terms of artificial selection and augmentation does not stop evolution from being true. It's like arguing against the four fundamental forces because the atomic bomb kills people.
Besides, artificial selection has been around from before the time of agriculture. Dogs were domesticated around 15,000 years ago, about 5,000 years before crops. We've been selecting species as pets, as food and as transport for several millennia. Not to mention that immoral behaviour has been around ever since we derived systems of morality. The moral implications of teaching evolutionary theory are unfounded.
The origin of life
The straw-man surrounding arguments against evolution because it does not explain the origin of life is precisely that: evolution does not explain the origin of life. It's not an argument against evolution, any more than saying evolution doesn't explain gravity. Evolution is a theory on how life has changed and diversified over the course of life on earth, it's not a theory of how life came to be in the first place.
Take another scientific theory: plate tectonics. Plate tectonics talk about the movement of the earth's lithosphere. The observations have been made to confirm this phenomenon. But we don't know how the earth formed the lithosphere in the first place, does that invalidate plate tectonics despite the evidence that it's happening? The same applies for evolution, the origin of life is something that needs explaining but evolution doesn't need an explanation of the origin of life to be true.
The straw man involving God when it comes to evolution is that evolution has nothing to say on the existence of God. Those who say that if evolution happened then God doesn't exist are putting up a false dichotomy between the two options. If God is defeated by naturalistic explanations then a belief in God would have been killed long ago. Seasons, weather, natural disasters, planetary motion / formation, disease, all these have naturalistic explanations that were once attributed to various deities. What makes evolution a God-killer when gravity is not? Angels pushing the planets across the sky is a silly explanation for planetary movement, as is that God hand crafted us out of dirt then breathed life into us.
There are many more straw-man attacks that are used, those are just a few that I come across repeatedly. What it does is build up to the biggest straw-man of all: that knocking down evolution proves creation. Just as it would be a straw-man to think that by dispelling creationism that evolution is true. The truth of evolution or creation, or any other concept for that matter, is whether it's supported by the evidence. Evolution is, creationism isn't. Trying to beat one down to prove the other is poor arguing.