I'm gonna be original as well and say Charlie!

Since he's the main character to the series, I learn more about him then we do with the other characters and I have a stronger "attachment" (so to say) to him. Plus I really like his personality. Funny, intelligent, quick thinking, and tries to do the right thing while also being arrogant and selfish. (Multiple personalities rule! XD )
Since you're asking us to elaborate on why our favorite characters are our favorites, it's only fair that you should do the same as well.