There is a collection of wonderful characters in the very best of the bunch.
In of Barney, the person within the show, even if the character is adored, is not perfect. Barney has many traits that define him, and while some are positive, others not so much.
Best - Unashamed
In some ways, Barney's unbelievable lack of shame is a bad thing, specifically when it comes to his pride in his sexual conquests. But, apart from that, it is pretty irable.
Barney does not care what people think about his magic, his love of laser tag, his blog, or his love of suits; he loves those things and has no shame about it.
Worst - Liar
It gets established time and time again that Barney is not only a talented liar but an incredibly compulsive liar, doing it consistently in just about every situation.
Barney even knows about his lying, itting to Robin that lies and deception are who he is. That obviously does not make things any better, though, as he uses his lying in insane ways to get women, and then in regular day-to-day life.
Best - Determined
Going back to the idea of Barney's best traits aiding in his worst hobbies, namely his insane levels of womanizing, Barney is a relentlessly determined individual.
This is another irable trait when it gets applied to positive or just non-awful things such as getting Robin to marry him, or accepting various challenges. Barney rarely gives up.
Worst - Naive
Barney has an extremely touchy family history, with an incredibly troubling upbringing aiding hugely in how messed up he is as an adult.
One thing that comes abundantly clear every time Barney's childhood gets brought up is that he is incredibly naive. While he its to knowing things like Bob Barker being his father are incorrect, he believes nearly everything his mother told him growing up, something to which James can attest.
Best - Loves His Family
Sticking with Barney and his family, growing up with his mother and brother, only made them pretty tight-knit, and one of Barney's most irable features is his love for them.
Even if he does blindly follow every word that comes out of his mouth, his undeniable love for her shines through as proven by the sociopathic lengths he goes through to make her happy. On top of that, he treats James like his idol, and it is a joy to watch.
Worst - Arrogant
Barney's challenges got mentioned earlier and while they highlight his determination, they also are a significant part of how arrogant Barney can be.
From the constant ission of his own awesomeness, his desire to be the center of attention at all times, his belief that every woman is attracted to him, and just a general air of superiority, Barney is very arrogant, even if he is utterly insecure.
Best - Loyal To His Friends
Barney may treat people he does not know pretty badly, and even his friends with basic insults, banter, and judgments, he is entirely loyal and devoted to his group of friends.
There are many examples of this, such as his determination to get Ted's approval for his relationship with Robin, or his traveling to San Francisco to get Lily and Marshall back together. He loves his family, he loves his friends, and they are one and the same.
Worst - Judgemental
As mentioned, Barney is very insulting towards his friends, as well as strangers, and pretty much all of these insults are judgments directed towards the various flaws he sees in them.
On top of the judgments he directs towards Ted for his dress sense, Marshall for his number of sexual partners, and Robin for being Canadian, Barney judges overweight women, women over thirty, and various other people.
Best - Cares Deep Down
Barney's insecurities have gotten talked about multiple times, and those insecurities have made Barney form a tough exterior, with a bro outlook on life, and a whole slew of issues.
However, deep down, Barney does appear to have a good heart and care about people, of course, his mother, brother, and friends, but also eventually his daughter, and can be a genuinely warm person who has suffered through a lot.
Worst - Treatment Of Women
Then again, for most of the show, Barney is the devil. We may love him, and he may be hilarious, but for the most part, his treatment of women is nothing short of deplorable.
His skills at womanizing may be legen-wait for it-dary, but it is also disgusting. The pride he takes in it, the lengths he goes to, the potential selling of a woman, it is undoubtedly Barney's worst trait.