Kyle Broflovski
This ten year old boy attends South Park Elementary, and is in the fourth grade (currently) along with his best friend Stan Marsh, and his other two friends Eric Cartman and Kenny McCormick.
Kyle is Jewish, as we discover early on in the series. He is most often seen wearing a green ushanka, orange coat, dark green pants and green mittens. His hair is red and curly (Ginger cute-ness FTW) and most fanart suggests that his eyes could possibly be green (though it is obviously never officially seen or stated in the show.) Kyle's various looks will be shown in the glorious Gallery section!
He is often portrayed as the "smart" one in the group, often siding with Stan in the finer points of logic and reason. Normally sweet and caring, he can lose his temper pretty quickly, resulting in short bursts of violence towards others (usually Cartman.) Like the other children, he is no stranger to cursing and flinging insults when provoked (again, normally towards Cartman.)
His compassion and imagination certainly shine through, and he is easily one of the more complex characters on the show, having to go through crazy and often life-threatening situations with his friends and forcing to choose between using his emotions or logical thinking.
Kyle has a mother named Sheila, father named Gerald, and an adopted Canadian brother, Ike. His interactions with his family are mixed. He sometimes expresses anger towards his parents for being too bossy, and at other times he will defend them. He is easily upset when Cartman sings "Kyle's Mom is a Bitch," and he refers to his dad as the "smartest guy in the world." But his love for his family is most present during his interactions with Ike. Kyle is shown to defend his little brother, and love him very much. Even though there are times when they fight and Kyle becomes annoyed with him, they share a strong brotherly bond. Isn't that just so friggin' adorable? :D
Note: There is a separate category named "Pairings", that goes deeper into his relationships with the other main three, as well as my analysis on each of these fanon shippings: Style, Kyman and K2.