There's no best in Mario Kart. There's only how well you did in the first few seconds of the race and what items you get. Oh, and there's some skill yeah. Speed advantages are negligible. I bet people use them only because they see other people use them especially in time trials where those miniscule milliseconds mean something.
Funky Kong is not annoying, he is funny. Same with Daisy.
Can't say the same for Yoshi. Yoshi is not shouty, Yoshi shrieks at a frequency that's like a whiny baby character from a baby show that acts stupid for the sake of a baby show.