1. Just-world hypothesis
2. Confirmation Bias
3. Ad hom/Halo Effect
4. Fundamental Attribution Error
I thought I'd throw these out there since I know that lots of people make these mistakes. Now, my good readers
, you will have improved as human beings!!! 
Captcha: creative vision
[footnote]Sources:
http://en.wikipedia.org/wiki/Just-world_hypothesis
http://en.wikipedia.org/wiki/Fundamental_attribution_error
http://en.wikipedia.org/wiki/Ad_hom
http://en.wikipedia.org/wiki/Confirmation_bias[/footnote]
The just-world hypothesis (or just-world fallacy) is a cognitive bias referring to the common assumption that situations and situational outcomes are caused or guided by some universal force of justice, order, stability, or desert. In other words, the just-world hypothesis is people's tendency to attribute consequences to, or expect consequences as the result of, a cosmic power responsible for the righting of past wrongs, injustices, or imbalances. The premise of the fallacy popularly appears in English in the form of various figures of speech, which often imply a negative reprisal of justice, such as: "You got what was coming to you," "What goes around comes around," and "You reap what you sow."
2. Confirmation Bias
Confirmation bias (also called confirmatory bias, myside bias or verification bias) is a tendency of people to favor information that confirms their beliefs or hypotheses.[Note 1][1] People display this bias when they gather or remember information selectively, or when they interpret it in a biased way. The effect is stronger for emotionally charged issues and for deeply entrenched beliefs. For example, in reading about gun control, people usually prefer sources that affirm their existing attitudes. They also tend to interpret ambiguous evidence as supporting their existing position. Biased search, interpretation and memory have been invoked to explain attitude polarization (when a disagreement becomes more extreme even though the different parties are exposed to the same evidence), belief perseverance (when beliefs persist after the evidence for them is shown to be false), the irrational primacy effect (a greater reliance on information encountered early in a series) and illusory correlation (when people falsely perceive an association between two events or situations).
3. Ad hom/Halo Effect
Ad hominem arguments work via the halo effect, a human cognitive bias in which the perception of one trait is influenced by the perception of an unrelated trait, e.g. treating an attractive person as more intelligent or more honest. People tend to see others as tending to all good or tending to all bad. Thus, if you can attribute a bad trait to your opponent, others will tend to doubt the quality of their arguments, even if the bad trait is irrelevant to the arguments.
4. Fundamental Attribution Error
In social psychology, the fundamental attribution error (also known as correspondence bias or attribution effect) describes the tendency to over-value dispositional or personality-based explanations for the observed behaviors of others while under-valuing situational explanations for those behaviors. The fundamental attribution error is most visible when people explain the behavior of others. It does not explain interpretations of one's own behavior?where situational factors are often taken into consideration. This discrepancy is called the actor?observer bias.
As a simple example, if Alice saw Bob trip over a rock and fall, Alice might consider Bob to be clumsy or careless (dispositional). If Alice tripped over the same rock herself, she would be more likely to blame the placement of the rock (situational).
I thought I'd throw these out there since I know that lots of people make these mistakes. Now, my good readers
Captcha: creative vision
[footnote]Sources:
http://en.wikipedia.org/wiki/Just-world_hypothesis
http://en.wikipedia.org/wiki/Fundamental_attribution_error
http://en.wikipedia.org/wiki/Ad_hom
http://en.wikipedia.org/wiki/Confirmation_bias[/footnote]