Harry Dresden -- Tony Hale. (You all keep coming up with pretty boys for Dresden. He's NOT. He's a tall, skinny, gangly geek who won't make eye contact with anyone and only turns into a bad ass when magic is involved. The rest of the time he's total geek.)
Bah, Tony Hale is 6'1. He's not tall. Tall enough, maybe, but not tall. And he's 43 now, meaning he'd be nearly 20 years older than Harry in SF.
If I want tall, skinny, gangly geek, Zachary Levi is my pick. At 6'4", he's close to Dresden's height, he's skinny as a rail, and he does geek very well. At 33, with two books a year, he'd be around 43-44 when the series completed.