I guess that the character from The Importance of Being Earnest that resembles Wilde most would be Algernon.
He is flamboyant, and a party-maniac, and loves to make fun of other people who are not like him. Wilde was like that in his real life too - he was a Victorian man but completely against that period, and he loved to express himself in a manner that would often weird out other people. Algernon is Wilde's voice in the play - he comments on other characters and criticizes them for their exaggerated Victorian values that Wilde hated with a passion.
