Update June 2011: Nikolaj has been in a lot of tv shows since the 90's before landing the role of Jaime Lannister. Although my first thoughts when I saw him as Jaime was that he wasn't dashingly handsome enough, he's grown on me and find him okay as Jaime.
I imagined Matthew McConaughey as Jaime while reading the books because he looked great with the golden locks and later on, without it. I mean, look the photos below (especially when he had no hair)... that's Jaime Lannister!
Kingslayer, Jaime Lannister is the younger twin to Cersei, and son of Tywin and Joanna in the novel series A Song of Ice and Fire. Jaime is one of the most famous knights in all of Westeros. At fifteen, he became a knight and ascended to the elite Kingsguard, the members of which can neither hold lands nor marry. Two years after his induction he murdered Mad King Aerys during the sack of King's Landing, earning him the nickname "Kingslayer". Though he shares his sister's arrogance and striking good looks, he is much more reckless and easily amused.
I know that Matthew McConaughey looks nothing like Angelina but when it mentioned in the books of golden curls and good looks, I imagined Matthew McConaughey as Jaime.