Good one!
BTW, all the negative traits that people have mentioned so far–I have all of them, too. But then I always was an overachiever. 
If I say I’m going to do something, it is done. I’m an Old New Englander, and we are the most tenacious people on the planet. Ask the Patriots. They were going to win that Super Bowl.
I forget no wrongs done to me. To quote Sheldon Cooper: I have an eidetic memory. Sometimes it’s a curse.
Like: I’m a great listener, I’m adaptable and easy going, and I’m hilarious
Dislike: I procrastinate like a mofo, I’m terrible with money, and I’m cynical
I like: That I’m a chronic improviser.
I dislike: That I’m a chronic improviser.
There is many other things, but this is probably my most important characteristic.
I Like: I am super empathetic, I’m a great listener, I am extremely reliable, I am well-spoken
I dislike: I am incredibly un-ambitious. I could be so much more in life but…meh.
Like: ability to multitask and work efficiently.
Dislike. Despite the fact that I work hard and accomplish a lot, I don’t care much for the fact I’m so lazy. I work hard because I want to get the job done and relax.
Like: my wit
Dislike: addictive personality
My favorite personality trait is that I’m fun to be around. As one friend put it, “You help others get out of their shells.”
My least favorite personality trait is that I sometimes feel inclined to not like people for stupid reasons without giving them a fair chance.
Im dubious as to whether this is even a real thing. Addiction is complicated.
I just don’t believe it’s as black and white as a choice between “addictive personality” or “nonaddictive personality”. Like so many things, I think risk factors for addiction exist on a spectrum.
Pro: I’m generous
Con: I lack self-discipline when it comes to taking care of my needs. Last night I finished work at 10 PM, and I knew I had to wake up early this morning. So I stayed up until 1 AM reading. I’ve been tired all day, and now I’m writing this post instead of resting.
Yes that did happen with me ! My mom and ex brother (I have nothing to do with my brother anymore so I can him an ex ) were in the kitchen talking very softly and when I walked in they both stop talking . I said " You’re having a baby!" to my ex brother . I didn’t hear a word they had said and they both were shocked about how I knew . I was right . Part of the reason I am so good at this was being hard of hearing and not getting my first hearing aid until I was 8 yo . I learned how to read people body language especially my dad . No I never did read about "highly sensitive people I will have to check it .
AHA! I knew you had to be good at something. 
Being able to read people and situations like this is not nothing, even if you learned it unwillingly at the School of Hard Knocks. There are some people who are totally clueless about what is going on all around them. That is not you. This is definitely something to like about yourself.
I predict you will see yourself all over this stuff. I know I did.
Like: I’m generous and caring sometimes.
Dislike: My personality is not consistent.
Don’t feel bad, I often stay up past 2 AM.
There’s part of me that wants to participate in this thread, but I have this tendency not to assign value to any of my attributes whatsoever. Nothing about me is good; nothing about me is bad. I merely exist, with no objective value whatsoever.
I’d like for you to participate, but you obviously don’t have to.
How about it?
Other people have complimented for various things related to my intelligence - my sharp wit and sense of humor, my ability to cut through problems at work like a sharp knife through badly implemented butter, and so on. (I’m not certain that intelligence is a ‘personality/character trait’, though.)
From the perspective of others, I suppose a bad thing about me is my incredible introversion and massive shyness, that sort of thing. To myself it’s not that much of a problem, though I do recognize that my odds of finding a romantic partner have probably been hampered a mite by the fact I never leave the house.
Things I like about myself: I’m very good at seeing all sides of an issue. I may not agree with some of them, but I can at least see where the other person is coming from.
Things I dislike about myself: I have seriously bad ADD that is nonresponsive to medication. Because of this I’ve never gotten a degree, and I struggle constantly with staying focused at work.
I wish I was more adventurous. I don’t like high speeds, I don’t like heights where I am not secured, anything that gives me a feeling of not being in control of my environment makes me uncomfortable. Large surging crowds, grizzly bears I don’t have a personal relationship with, things like this. I often avoided trips with my buddies to avoid situations like this. Funny thing is most of my buddies are scared to death of getting into a fight or getting jumped where I have very little fear of that. Big dogs I have a healthy respect for and I am able to stay calm enough around aggressive dogs to at least read them pretty good.