Harry: like everyone said, he has a hard time controlling his temper, he's impatient, and a bit nosy. Like they say, curiosity killed the cat, except in Harry's case, it got him into a lot of trouble many times!😃 He's my favorite of the Trio though.
Ron: Insensitive at times, though he is a great friend, gets jealous easily, and many times doesn't understand others until it causes a fight or whatnot.
Hermione: Proud (she knows she's smart), she doesn't believe "far-fetched ideas" though they have been proven true in many cases (i.e. Deathly Hallows), gets upset very easily, and is uptight.
Neville: Let's what others say get to him (though I was happy to see that he grew out of that in HBP and DH) and low self-esteem.
Luna: Sometimes insensitive in her day-dreaming (she doesn't realize it when she hurts people though she doesn't mean it), takes any situation (no matter how serious it is) too lightly, and is always in her own little world despite what's going on around her.
Ginny: Stubborn (too stubborn), gets offended very easily, a little jealous of Harry's other girlfriends (cough*cough* Cho), and makes hasty decisions that often get her into trouble; a bit like Harry in that😉.
Dumbledore: Underestimates people, places too much trust in others despite whether they're death eaters or not, and expects others to be as intelligent as him in deducing the answers to situations. Old Dumbly is my fav character though.⭐️
Snape: Never forgives a mistake, torments the son of his enemy though the son never did anything to him (conveniently forgets that the boy is the son of his true love as well), is extremely prejudicial to any house other than Slytherin to the point of completely ignoring the misdeeds of those of his own house, and forgets the wrongs he committed to others while only remembering (and holding a life long grudge) the wrongs others committed to him\
There are a ton of other characters, but I don't have time to do them right now.😳
One thing I love about Harry Potter (the series): every character has one or more flaw, and no one (absolutely no one) is perfect.