Yay!! Whoa that's so hard. I like so many characters... hmm I'm torn between Kyubei and Tsukuyo when it comes to the female characters. Gintoki is definitely my favourite male character How about you?
My favourites are Takasugi, Gintoki, Sougo and Hijikata. From female characters, I think Tsukuyo and Mitsuba. But almost all characters are so awesome that it's difficult to choose. I love pretty much all of them!