Is there a word for someone who tends to find faults in others?

Solution 1:

I just cannot resist mentioning the term nitpicker here.

a person given to harsh judgments and to finding faults

"a tiresome nitpicker who seems to think that I can't do anything right"

reference http://www.merriam-webster.com/thesaurus/nitpicker

Solution 2:

• Captious.

1 : marked by an often ill-natured inclination to stress faults and raise objections

http://i.word.com/idictionary/captious

Solution 3:

Such a person could be called 'Judgemental'

Judgemental: Having or displaying an overly critical point of view

Solution 4:

If you don't like fault-finder, there's the verb carp:

carp (v.) to complain or find fault; nag pettily

The noun form is carper, but that's not a very common word.

Solution 5:

keeps seeing everything that is wrong with everybody else.

That person is overly critical: expressing adverse or disapproving comments or judgments.

never seems to see the good of other people, only the bad things.

That person is pessimistic: tending to see the worst aspect of things or believe that the worst will happen.

points at others, as if he forgets he has weaknesses himself.

That person is hypocritical: behaving in a way that suggests one has higher standards or more noble beliefs than is the case.

does not brag about himself, he just seems to be dissatisfied with everyone else.

That person is cantankerous: bad-tempered, argumentative, and uncooperative.