I really dislike Mirage. I used to dislike Violet too, but it was because in the public’s eye she has outshined the main characters, who are in my eyes less annoying and better developed. It’s kind of funny looking back, I literally used to watch this movie once a week or more. And it was always a mixture of euphoria and raging at half the cast. I even got angry when Edna slapped Helen with the news paper. 
One other favorite character–Tony (Violet’s crush)
I think Kari is my favorite. 
Mine is Violet! I relate the most to her, she has the best powers, and she’s voiced by one of my favorite authors/historians.
Violet hands down will always be top girl in my heart (with Helen, Dash and Mirage all get honors as they were all well written), in fact I own actual plush of her that I bought on Amazon last year (the Incredibles symbol is worn off sadly), also Violet is voiced by an author/novelist (which all we know and love).
I’ve grown to appreciate all the characters in the film for the respective roles they play. But my favorites will always be Bob for his tremendous character growth and Helen for constantly supporting and loving her family.
I love them all, but my favorites are Violet, Dash, Helen, Bob, and Edna Mode.